cisco ios lan switching configuration guide, release 12.4
TRANSCRIPT
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Cisco IOS LAN Switching Configuration GuideRelease 12.4
Customer Order Number: DOC-7817486=Text Part Number: 78-17486-01
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Cisco IOS LAN Switching Configuration Guide© 2005–2006 Cisco Systems, Inc. All rights reserved.
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iiiCisco IOS LAN Switching Configuration Guide
C O N T E N T S
About Cisco IOS Software Documentation for Release 12.4 xix
Documentation Objectives xix
Audience xix
Documentation Organization for Cisco IOS Release 12.4 xx
Document Conventions xxvi
Obtaining Documentation xxvii
Cisco.com xxvii
Product Documentation DVD xxviii
Ordering Documentation xxviii
Documentation Feedback xxviii
Cisco Product Security Overview xxix
Reporting Security Problems in Cisco Products xxix
Obtaining Technical Assistance xxx
Cisco Technical Support & Documentation Website xxx
Submitting a Service Request xxx
Definitions of Service Request Severity xxxi
Obtaining Additional Publications and Information xxxi
Using Cisco IOS Software for Release 12.4 xxxiii
Understanding Command Modes xxxiii
Getting Help xxxiv
Example: How to Find Command Options xxxv
Using the no and default Forms of Commands xxxviii
Saving Configuration Changes xxxviii
Filtering Output from the show and more Commands xxxix
Finding Additional Feature Support Information xxxix
PART 1: VIRTUAL LANS
Virtual LANS Features Roadmap 3
Configuring Routing Between VLANs 7
Contents 7
Information About Routing Between VLANs 7
Contents
ivCisco IOS LAN Switching Configuration Guide
Virtual Local Area Network Definition 8
LAN Segmentation 8
Security 9
Broadcast Control 9
VLAN Performance 10
Network Management 10
Network Monitoring Using SNMP 10
Communication Between VLANs 10
Relaying Function 10
Native VLAN 12
PVST+ 13
Ingress and Egress Rules 14
Integrated Routing and Bridging 14
VLAN Colors 14
Implementing VLANS 15
Communication Between VLANs 15
Inter-Switch Link Protocol 15
IEEE 802.10 Protocol 16
IEEE 802.1Q Protocol 16
ATM LANE Protocol 16
ATM LANE Fast Simple Server Replication Protocol 16
VLAN Interoperability 17
Inter-VLAN Communications 17
VLAN Translation 18
Designing Switched VLANs 18
How to Configure Routing Between VLANS 18
Configuring a VLAN Range 18
Restrictions 19
Supported Platforms 19
Benefits 19
Configuring a Range of VLAN Subinterfaces 19
Configuring Routing Between VLANs with Inter-Switch Link Encapsulation 21
Frame Tagging in ISL 21
Configuring AppleTalk Routing over ISL 22
Configuring Banyan VINES Routing over ISL 24
Configuring DECnet Routing over ISL 25
Configuring the Hot Standby Router Protocol over ISL 26
Configuring IP Routing over TRISL 28
Configuring IPX Routing on 802.10 VLANs over ISL 29
Configuring IPX Routing over TRISL 31
Contents
vCisco IOS LAN Switching Configuration Guide
Configuring VIP Distributed Switching over ISL 32
Configuring XNS Routing over ISL 34
Configuring CLNS Routing over ISL 35
Configuring IS-IS Routing over ISL 36
Configuring Routing Between VLANs with IEEE 802.10 Encapsulation 37
Configuring Routing Between VLANs with IEEE 802.1Q Encapsulation 39
Prerequisites 39
Restrictions 39
Configuring AppleTalk Routing over IEEE 802.1Q 40
Configuring IP Routing over IEEE 802.1Q 41
Configuring IPX Routing over IEEE 802.1Q 42
Configuring a VLAN for a Bridge Group with Default VLAN1 43
Configuring a VLAN for a Bridge Group as a Native VLAN 44
Configuring IEEE 802.1Q-in-Q VLAN Tag Termination 45
Prerequisites 45
Restrictions 46
IEEE 802.1Q-in-Q VLAN Tag Termination on Subinterfaces 46
Cisco 10000 Series Internet Router Application 47
Security ACL Application on the Cisco 10000 Series Internet Router 48
Unambiguous and Ambiguous Subinterfaces 49
Prerequisites 49
Configuring EtherType Field for Outer VLAN Tag Termination 50
Configuring the Q-in-Q Subinterface 50
Verifying the IEEE 802.1Q-in-Q VLAN Tag Termination 52
Monitoring and Maintaining VLAN Subinterfaces 55
Example 55
Configuration Examples for Configuring Routing Between VLANs 56
Single Range Configuration: Example 56
ISL Encapsulation Configuration: Examples 57
AppleTalk Routing over ISL Configuration: Example 58
Banyan VINES Routing over ISL Configuration: Example 59
DECnet Routing over ISL Configuration: Example 59
HSRP over ISL Configuration: Example 59
IP Routing with RIF Between TrBRF VLANs: Example 61
IP Routing Between a TRISL VLAN and an Ethernet ISL VLAN: Example 62
IPX Routing over ISL Configuration: Example 62
IPX Routing on FDDI Interfaces with SDE: Example 64
Routing with RIF Between a TRISL VLAN and a Token Ring Interface: Example 64
VIP Distributed Switching over ISL Configuration: Example 65
XNS Routing over ISL Configuration: Example 66
Contents
viCisco IOS LAN Switching Configuration Guide
CLNS Routing over ISL Configuration: Example 66
IS-IS Routing over ISL Configuration: Example 67
Routing IEEE 802.10 Configuration: Example 67
IEEE 802.1Q Encapsulation Configuration: Examples 68
Configuring AppleTalk over IEEE 802.1Q: Example 68
Configuring IP Routing over IEEE 802.1Q: Example 68
Configuring IPX Routing over IEEE 802.1Q: Example 69
VLAN 100 for Bridge Group 1 with Default VLAN1: Example 69
VLAN 20 for Bridge Group 1 with Native VLAN: Example 69
VLAN ISL or IEEE 802.1Q Routing: Example 69
VLAN IEEE 802.1Q Bridging: Example 70
VLAN IEEE 802.1Q IRB: Example 71
Configuring IEEE 802.1Q-in-Q VLAN Tag Termination: Example 72
Additional References 74
Related Documents 74
Standards 74
MIBs 74
RFCs 75
Technical Assistance 75
Feature Information for Routing Between VLANs 76
Managed LAN Switch 77
Contents 77
Information About Managed LAN Switch 78
LAN Switching 78
How to Enable Managed LAN Switch 78
Enabling Managed LAN Switch 78
Verifying Managed LAN Switch 79
Configuration Examples for Managed LAN Switch 80
Enabling Managed LAN Switch: Example 80
Additional References 80
Related Documents 80
Standards 81
MIBs 81
RFCs 81
Technical Assistance 81
Command Reference 81
Cisco HWIC-4ESW and HWIC-D-9ESW EtherSwitch Interface Cards 83
Contents 83
Contents
viiCisco IOS LAN Switching Configuration Guide
Prerequisites for EtherSwitch HWICs 84
Restrictions for EtherSwitch HWICs 84
Prerequisites for Installing Two Ethernet Switch Network Modules in a Single Chassis 84
Information About EtherSwitch HWICs 85
VLANs 85
Inline Power for Cisco IP Phones 85
Layer 2 Ethernet Switching 85
802.1x Authentication 86
Spanning Tree Protocol 86
Cisco Discovery Protocol 86
Switched Port Analyzer 86
IGMP Snooping 86
Storm Control 86
Intrachassis Stacking 86
Fallback Bridging 87
How to Configure EtherSwitch HWICs 87
Configuring VLANs 87
Adding a VLAN Instance 87
Deleting a VLAN Instance from the Database 90
Configuring VLAN Trunking Protocol 92
Configuring a VTP Server 92
Configuring a VTP Client 93
Disabling VTP (VTP Transparent Mode) 94
Verifying VTP 95
Configuring Layer 2 Interfaces 95
Configuring a Range of Interfaces 96
Defining a Range Macro 96
Configuring Layer 2 Optional Interface Features 97
Configuring 802.1x Authentication 105
Information About the Default 802.1x Configuration 105
Enabling 802.1x Authentication 107
Configuring the Switch-to-RADIUS-Server Communication 108
Enabling Periodic Reauthentication 110
Changing the Quiet Period 111
Changing the Switch-to-Client Retransmission Time 112
Setting the Switch-to-Client Frame-Retransmission Number 114
Enabling Multiple Hosts 115
Resetting the 802.1x Configuration to the Default Values 116
Displaying 802.1x Statistics and Status 117
Contents
viiiCisco IOS LAN Switching Configuration Guide
Configuring Spanning Tree 117
Enabling Spanning Tree 118
Configuring Spanning Tree Port Priority 119
Configuring Spanning Tree Port Cost 120
Configuring the Bridge Priority of a VLAN 123
Configuring Hello Time 124
Configuring the Forward-Delay Time for a VLAN 124
Configuring the Maximum Aging Time for a VLAN 125
Configuring the Root Bridge 126
Configuring MAC Table Manipulation 127
Enabling Known MAC Address Traffic 128
Creating a Static Entry in the MAC Address Table 129
Configuring and Verifying the Aging Timer 130
Configuring Cisco Discovery Protocol 131
Enabling Cisco Discovery Protocol 131
Enabling CDP on an Interface 132
Monitoring and Maintaining CDP 134
Configuring the Switched Port Analyzer (SPAN) 135
Configuring the SPAN Sources 135
Configuring SPAN Destinations 136
Example 137
Configuring Power Management on the Interface 137
Example 138
Configuring IP Multicast Layer 3 Switching 139
Enabling IP Multicast Routing Globally 139
Enabling IP Protocol-Independent Multicast (PIM) on Layer 3 Interfaces 140
Verifying IP Multicast Layer 3 Hardware Switching Summary 141
Verifying the IP Multicast Routing Table 142
Configuring IGMP Snooping 143
Enabling or Disabling IGMP Snooping 143
Enabling IGMP Immediate-Leave Processing 145
Statically Configuring an Interface to Join a Group 146
Configuring a Multicast Router Port 148
Configuring Per-Port Storm Control 149
Enabling Per-Port Storm Control 149
Disabling Per-Port Storm Control 150
Configuring Stacking 152
Configuring Fallback Bridging 154
Understanding the Default Fallback Bridging Configuration 154
Creating a Bridge Group 155
Contents
ixCisco IOS LAN Switching Configuration Guide
Preventing the Forwarding of Dynamically Learned Stations 156
Configuring the Bridge Table Aging Time 158
Filtering Frames by a Specific MAC Address 159
Adjusting Spanning-Tree Parameters 160
Adjusting BPDU Intervals 164
Monitoring and Maintaining the Network 169
Configuring Separate Voice and Data Subnets 169
Voice Traffic and VVID 170
Configuring a Single Subnet for Voice and Data 171
Managing the EtherSwitch HWIC 172
Adding Trap Managers 172
Configuring IP Information 173
Enabling Switch Port Analyzer 177
Managing the ARP Table 178
Managing the MAC Address Tables 178
Removing Dynamic Addresses 180
Adding Secure Addresses 181
Configuring Static Addresses 183
Clearing All MAC Address Tables 185
Configuration Examples for EtherSwitch HWICs 185
Range of Interface: Examples 186
Single Range Configuration: Example 186
Range Macro Definition: Example 186
Optional Interface Feature: Examples 186
Interface Speed: Example 186
Setting the Interface Duplex Mode: Example 187
Adding a Description for an Interface: Example 187
Stacking: Example 187
VLAN Configuration: Example 187
VLAN Trunking Using VTP: Example 187
Spanning Tree: Examples 188
Spanning-Tree Interface and Spanning-Tree Port Priority: Example 188
Spanning-Tree Port Cost: Example 189
Bridge Priority of a VLAN: Example 190
Hello Time: Example 190
Forward-Delay Time for a VLAN: Example 190
Maximum Aging Time for a VLAN: Example 190
Spanning Tree: Examples 190
Spanning Tree Root: Example 191
MAC Table Manipulation: Example 191
Contents
xCisco IOS LAN Switching Configuration Guide
Switched Port Analyzer (SPAN) Source: Examples 191
SPAN Source Configuration: Example 191
SPAN Destination Configuration: Example 191
Removing Sources or Destinations from a SPAN Session: Example 191
IGMP Snooping: Example 191
Storm-Control: Example 193
Ethernet Switching: Examples 193
Subnets for Voice and Data: Example 194
Inter-VLAN Routing: Example 194
Single Subnet Configuration: Example 195
Ethernet Ports on IP Phones with Multiple Ports: Example 195
Additional References 195
Related Documents 195
Standards 196
MIBs 196
RFCs 196
Technical Assistance 196
Command Reference 197
Feature Information for the Cisco HWIC-4ESW and the Cisco HWIC-D-9ESW EtherSwitch Cards 198
EtherSwitch Network Module 199
Contents 199
Prerequisites for the EtherSwitch Network Module 200
Restrictions for the EtherSwitch Network Module 200
Information About the EtherSwitch Network Module 201
EtherSwitch Network Module: Benefits 201
Ethernet Switching in Cisco AVVID Architecture 202
VLANs 202
Inline Power for Cisco IP Phones 204
Using the Spanning Tree Protocol with the EtherSwitch network module 204
Layer 2 Ethernet Switching 216
Cisco Discovery Protocol 218
Port Security 218
802.1x Authentication 218
Storm Control 222
EtherChannel 224
Flow Control on Gigabit Ethernet Ports 224
Intrachassis Stacking 225
Switched Port Analyzer 225
Contents
xiCisco IOS LAN Switching Configuration Guide
Switched Virtual Interface 227
Routed Ports 227
IP Multicast Layer 3 Switching 227
IGMP Snooping 228
Fallback Bridging 230
Network Security with ACLs at Layer 2 232
Quality of Service for the EtherSwitch Network Module 235
How to Configure the EtherSwitch Network Module 241
Configuring VLANs 242
VLAN Removal from the Database 242
Examples 243
Configuring VLAN Trunking Protocol 244
VTP Mode Behavior 244
Examples 246
Configuring Spanning Tree on a VLAN 246
VLAN Root Bridge 246
VLAN Bridge Priority 247
Verifying Spanning Tree on a VLAN 249
Configuring Layer 2 Interfaces 251
Interface Speed and Duplex Mode Guidelines 251
Examples 253
Configuring an Ethernet Interface as a Layer 2 Trunk 254
Restrictions 254
Examples 255
Configuring an Ethernet Interface as a Layer 2 Access 256
Configuring Separate Voice and Data VLANs 257
Separate Voice and Data VLANs 257
Voice Traffic and Voice VLAN ID (VVID) Using the EtherSwitch Network Module 258
Configuring a Single Voice and Data VLAN 259
Single Voice and Data VLAN 259
Managing the EtherSwitch network module 260
Trap Managers 260
IP Addressing 261
IP Information Assigned to the Switch 261
Use of Ethernet Ports to Support Cisco IP Phones with Multiple Ports 261
Domain Name Mapping and DNS Configuration 261
ARP Table Management 262
Configuring Voice Ports 263
Port Connection to a Cisco 7960 IP Phone 264
Inline Power on an EtherSwitch Network Module 264
Contents
xiiCisco IOS LAN Switching Configuration Guide
Verifying Cisco Discovery Protocol 265
Configuring the MAC Table to Provide Port Security 266
MAC Addresses and VLANs 266
Address Aging Time 267
Secure Addresses 267
Static Addresses 267
Examples 269
Configuring 802.1x Authentication 269
802.1x Authentication Guidelines for the EtherSwitch network module 269
Enabling 802.1x Authentication 271
Configuring the Switch-to-RADIUS-Server Communication 273
Configuring 802.1x Parameters (Retransmissions and Timeouts) 274
Examples 277
Configuring Power Management on the Interfaces 278
Examples 279
Configuring Storm Control 279
Enabling Global Storm Control 279
Examples 280
Enabling Per-Port Storm Control 281
Examples 282
Configuring Layer 2 EtherChannels (Port-Channel Logical Interfaces) 282
Restrictions 282
Examples 284
Configuring Flow Control on Gigabit Ethernet Ports 285
Examples 286
Configuring Intrachassis Stacking 286
Configuring Switched Port Analyzer (SPAN) 287
Configuring Layer 3 Interfaces 288
Layer 3 Interface Support for the EtherSwitch network module 288
Enabling and Verifying IP Multicast Layer 3 Switching 290
Examples 291
Configuring IGMP Snooping 292
IGMP Snooping on the EtherSwitch Network Module 292
IGMP Immediate-Leave Processing 292
Static Configuration of an Interface to Join a Multicast Group 293
Configuring Fallback Bridging 294
Understanding the Default Fallback Bridging Configuration 295
Configuring a Bridge Group 295
Adjusting Spanning-Tree Parameters 298
Disabling the Spanning Tree on an Interface 300
Contents
xiiiCisco IOS LAN Switching Configuration Guide
Configuring Network Security with ACLs at Layer 2 301
Restrictions 301
Creating Standard and Extended IP ACLs 302
ACL Numbers 302
Including Comments About Entries in ACLs 303
Configuring a Numbered Standard ACL 303
Configuring a Numbered Extended ACL 305
What to Do Next 308
Configuring a Named Standard ACL 308
Configuring a Named Extended ACL 310
Applying the ACL to an Interface 311
Configuring Quality of Service (QoS) on the EtherSwitch network module 313
Prerequisites 313
Restrictions 313
QoS on Switching Devices 314
Trust State on Ports and SVIs Within the QoS Domain 314
Configuring Classification Using Port Trust States 315
Examples 317
Configuring a QoS Policy 317
Classifying Traffic by Using ACLs 317
Classifying Traffic Using Class Maps 317
Classifying, Policing, and Marking Traffic Using Policy Maps 319
Configuring the CoS-to-DSCP Map 322
Configuring the DSCP-to-CoS Map 323
Configuration Examples for the EtherSwitch Network Module 324
Configuring VLANs: Example 325
Configuring VTP: Example 325
Configuring Spanning Tree: Examples 326
Configuring Layer 2 Interfaces: Examples 327
Single Range Configuration: Example 327
Multiple Range Configuration: Example 327
Range Macro Definition: Example 328
Optional Interface Features: Example 328
Configuring an Ethernet Interface as a Layer 2 Trunk: Example 328
Configuring Voice and Data VLANs: Examples 328
Separate Voice and Data VLANs: Example 329
Inter-VLAN Routing: Example 329
Single Subnet Configuration: Example 330
Ethernet Ports on IP Phones with Multiple Ports: Example 330
Configuring 802.1x Authentication: Examples 330
Contents
xivCisco IOS LAN Switching Configuration Guide
Enabling 802.1x Authentication: Example 331
Configuring the Switch-to-RADIUS-Server Communication: Example 331
Configuring 802.1x Parameters: Example 331
Configuring Storm-Control: Example 331
Configuring Layer 2 EtherChannels: Example 332
Layer 2 EtherChannels: Example 332
Removing an EtherChannel: Example 332
Configuring Flow Control on Gigabit Ethernet Ports: Example 332
Intrachassis Stacking: Example 335
Configuring Switched Port Analyzer (SPAN): Example 336
Configuring Layer 3 Interfaces: Example 336
IGMP Snooping: Example 337
Configuring Fallback Bridging: Examples 339
Creating a Bridge Group: Example 339
Adjusting Spanning Tree Parameters: Example 340
Disabling the Spanning Tree on an Interface: Example 340
Fallback Bridging with DLSW: Example 340
Configuring Network Security with ACLs at Layer 2: Examples 341
Creating Numbered Standard and Extended ACLs: Example 342
Creating Named Standard and Extended ACLs: Example 342
Including Comments About Entries in ACLs: Example 343
Applying the ACL to an Interface: Example 343
Displaying Standard and Extended ACLs: Example 343
Displaying Access Groups: Example 344
Compiling ACLs: Example 345
Configuring QoS on the EtherSwitch network module: Examples 346
Classifying Traffic by Using ACLs: Example 347
Classifying Traffic by Using Class Maps: Example 347
Classifying, Policing, and Marking Traffic by Using Policy Maps: Example 347
Configuring the CoS-to-DSCP Map: Example 347
Configuring the DSCP-to-CoS Map: Example 348
Displaying QoS Information: Example 348
Additional References 349
Related Documents 349
Standards 349
MIBs 350
RFCs 350
Technical Assistance 351
Command Reference 351
Contents
xvCisco IOS LAN Switching Configuration Guide
Glossary 353
PART 2: MULTILAYER SWITCHING
Multilayer Switching Overview 359
Terminology 360
Introduction to MLS 360
Key MLS Features 361
MLS Implementation 362
Standard and Extended Access Lists 364
Restrictions on Using IP Router Commands with MLS Enabled 365
General Guidelines 365
Introduction to IP Multicast MLS 365
IP Multicast MLS Network Topology 365
IP Multicast MLS Components 367
Layer 2 Multicast Forwarding Table 367
Layer 3 Multicast MLS Cache 367
IP Multicast MLS Flow Mask 368
Layer 3-Switched Multicast Packet Rewrite 368
Partially and Completely Switched Flows 369
Introduction to IPX MLS 369
IPX MLS Components 370
IPX MLS Flows 370
MLS Cache 370
Flow Mask Modes 371
Layer 3-Switched Packet Rewrite 371
IPX MLS Operation 372
Standard Access Lists 373
Guidelines for External Routers 374
Features That Affect MLS 374
Access Lists 374
Input Access Lists 374
Output Access Lists 374
Access List Impact on Flow Masks 375
Reflexive Access Lists 375
IP Accounting 375
Data Encryption 375
Policy Route Maps 375
TCP Intercept 375
Contents
xviCisco IOS LAN Switching Configuration Guide
Network Address Translation 375
Committed Access Rate 375
Maximum Transmission Unit 376
Configuring IP Multilayer Switching 377
Configuring and Monitoring MLS 377
Configuring MLS on a Router 378
Monitoring MLS 379
Monitoring MLS for an Interface 380
Monitoring MLS Interfaces for VTP Domains 380
Configuring NetFlow Data Export 381
Specifying an NDE Address on the Router 381
Multilayer Switching Configuration Examples 381
Router Configuration Without Access Lists Example 381
Router Configuration with a Standard Access List Example 382
Router Configuration with an Extended Access List Example 383
Configuring IP Multicast Multilayer Switching 385
Prerequisites 385
Restrictions 386
Router Configuration Restrictions 386
External Router Guidelines 387
Access List Restrictions and Guidelines 387
Configuring and Monitoring IP Multicast MLS 387
Enabling IP Multicast Routing 388
Enabling IP PIM 388
Enabling IP Multicast MLS 388
Specifying a Management Interface 389
Monitoring and Maintaining IP Multicast MLS 389
IP Multicast MLS Configuration Examples 389
Basic IP Multicast MLS Network Examples 390
Network Topology Example 390
Operation Before IP Multicast MLS Example 391
Operation After IP Multicast MLS Example 391
Router Configuration 391
Switch Configuration 392
Complex IP Multicast MLS Network Examples 392
Network Topology Example 393
Operation Before IP Multicast MLS Example 394
Operation After IP Multicast MLS Example 394
Contents
xviiCisco IOS LAN Switching Configuration Guide
Configuring IPX Multilayer Switching 397
Prerequisites 397
Restrictions 398
General Configuration Guidelines 398
External Router Guidelines 398
Access List Restrictions 398
Restrictions on Interaction of IPX MLS with Other Features 399
Restriction on Maximum Transmission Unit Size 399
IPX MLS Configuration Task List 399
Adding an IPX MLS Interface to a VTP Domain 400
Enabling Multilayer Switching Protocol (MLSP) on the Router 400
Assigning a VLAN ID to a Router Interface 400
Enabling IPX MLS on a Router Interface 401
Specifying a Router Interface As a Management Interface 401
Verifying IPX MLS on the Router 401
Troubleshooting Tips 401
Monitoring and Maintaining IPX MLS on the Router 402
IPX MLS Configuration Examples 402
Complex IPX MLS Network Examples 402
IPX MLS Network Topology Example 403
Operation Before IPX MLS Example 404
Operation After IPX MLS Example 404
Switch A Configuration 404
Switch B Configuration 405
Switch C Configuration 405
MLS-RP Configuration 406
Router with No Access Lists Configuration 406
Configuring a Router with a Standard Access List Example 407
Contents
xviiiCisco IOS LAN Switching Configuration Guide
xixCisco IOS LAN Switching Configuration Guide
About Cisco IOS Software Documentation for Release 12.4
This chapter describes the objectives, audience, organization, and conventions of Cisco IOS software documentation. It also provides sources for obtaining documentation, technical assistance, and additional publications and information from Cisco Systems. It contains the following sections:
• Documentation Objectives, page xix
• Audience, page xix
• Documentation Organization for Cisco IOS Release 12.4, page xx
• Document Conventions, page xxvi
• Obtaining Documentation, page xxvii
• Documentation Feedback, page xxviii
• Cisco Product Security Overview, page xxix
• Obtaining Technical Assistance, page xxx
• Obtaining Additional Publications and Information, page xxxi
Documentation ObjectivesCisco IOS software documentation describes the tasks and commands available to configure and maintain Cisco networking devices.
AudienceThe Cisco IOS software documentation set is intended primarily for users who configure and maintain Cisco networking devices (such as routers and switches) but who may not be familiar with the configuration and maintenance tasks, the relationship among tasks, or the Cisco IOS software commands necessary to perform particular tasks. The Cisco IOS software documentation set is also intended for those users experienced with Cisco IOS software who need to know about new features, new configuration options, and new software characteristics in the current Cisco IOS software release.
About Cisco IOS Software Documentation for Release 12.4Documentation Organization for Cisco IOS Release 12.4
xxCisco IOS LAN Switching Configuration Guide
Documentation Organization for Cisco IOS Release 12.4The Cisco IOS Release 12.4 documentation set consists of the configuration guide and command reference pairs listed in Table 1 and the supporting documents listed in Table 2. The configuration guides and command references are organized by technology. For the configuration guides:
• Some technology documentation, such as that for DHCP, contains features introduced in Releases 12.2T and 12.3T and, in some cases, Release 12.2S. To assist you in finding a particular feature, a roadmap document is provided.
• Other technology documentation, such as that for OSPF, consists of a chapter and accompanying Release 12.2T and 12.3T feature documents.
Note In some cases, information contained in Release 12.2T and 12.3T feature documents augments or supersedes content in the accompanying documentation. Therefore it is important to review all feature documents for a particular technology.
Table 1 lists the Cisco IOS Release 12.4 configuration guides and command references.
Table 1 Cisco IOS Release 12.4 Configuration Guides and Command References
Configuration Guide and Command Reference Titles
Description
IP
Cisco IOS IP Addressing Services Configuration Guide, Release 12.4
Cisco IOS IP Addressing Services Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring IP addressing and services, including Network Address Translation (NAT), Domain Name System (DNS), and Dynamic Host Configuration Protocol (DHCP). The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS IP Application Services Configuration Guide, Release 12.4
Cisco IOS IP Application ServicesCommand Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring IP application services, including IP access lists, Web Cache Communication Protocol (WCCP), Gateway Load Balancing Protocol (GLBP), Server Load Balancing (SLB), Hot Standby Router Protocol (HSRP), and Virtual Router Redundancy Protocol (VRRP). The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS IP Mobility Configuration Guide, Release 12.4
Cisco IOS IP Mobility Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring Mobile IP and Cisco Mobile Networks. The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS IP MulticastConfiguration Guide, Release 12.4
Cisco IOS IP Multicast Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring IP multicast, including Protocol Independent Multicast (PIM), Internet Group Management Protocol (IGMP), Distance Vector Multicast Routing Protocol (DVMRP), and Multicast Source Discovery Protocol (MSDP). The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS IP Routing Protocols Configuration Guide, Release 12.4
Cisco IOS IP Routing Protocols Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring IP routing protocols, including Border Gateway Protocol (BGP), Intermediate System-to-Intermediate System (IS-IS), and Open Shortest Path First (OSPF). The command reference provides detailed information about the commands used in the configuration guide.
About Cisco IOS Software Documentation for Release 12.4Documentation Organization for Cisco IOS Release 12.4
xxiCisco IOS LAN Switching Configuration Guide
Cisco IOS IP Switching Configuration Guide, Release 12.4
Cisco IOS IP Switching Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring IP switching features, including Cisco Express Forwarding, fast switching, and Multicast Distributed Switching (MDS). The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS IPv6 Configuration Guide, Release 12.4
Cisco IOS IPv6 Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring IP version 6 (IPv6), including IPv6 broadband access, IPv6 data-link layer, IPv6 multicast routing, IPv6 quality of service (QoS), IPv6 routing, IPv6 services and management, and IPv6 tunnel services. The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS Optimized Edge Routing Configuration Guide, Release 12.4
Cisco IOS Optimized Edge Routing Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring Optimized Edge Routing (OER) features, including OER prefix learning, OER prefix monitoring, OER operational modes, and OER policy configuration. The command reference provides detailed information about the commands used in the configuration guide.
Security and VPN
Cisco IOS Security Configuration Guide, Release 12.4
Cisco IOS Security Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring various aspects of security, including terminal access security, network access security, accounting, traffic filters, router access, and network data encryption with router authentication. The command reference provides detailed information about the commands used in the configuration guide.
QoS
Cisco IOS Quality of Service Solutions Configuration Guide, Release 12.4
Cisco IOS Quality of Service Solutions Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring quality of service (QoS) features, including traffic classification and marking, traffic policing and shaping, congestion management, congestion avoidance, and signaling. The command reference provides detailed information about the commands used in the configuration guide.
LAN Switching
Cisco IOS LAN Switching Configuration Guide, Release 12.4
Cisco IOS LAN Switching Command Reference, Release 12.4
The configuration guide is a task-oriented guide to local-area network (LAN) switching features, including configuring routing between virtual LANs (VLANs) using Inter-Switch Link (ISL) encapsulation, IEEE 802.10 encapsulation, and IEEE 802.1Q encapsulation. The command reference provides detailed information about the commands used in the configuration guide.
Multiprotocol Label Switching (MPLS)
Cisco IOS Multiprotocol Label Switching Configuration Guide, Release 12.4
Cisco IOS Multiprotocol Label Switching Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring Multiprotocol Label Switching (MPLS), including MPLS Label Distribution Protocol, MPLS traffic engineering, and MPLS Virtual Private Networks (VPNs). The command reference provides detailed information about the commands used in the configuration guide.
Network Management
Cisco IOS IP SLAs Configuration Guide, Release 12.4
Cisco IOS IP SLAs Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring the Cisco IOS IP Service Level Assurances (IP SLAs) feature. The command reference provides detailed information about the commands used in the configuration guide.
Table 1 Cisco IOS Release 12.4 Configuration Guides and Command References (continued)
Configuration Guide and Command Reference Titles
Description
About Cisco IOS Software Documentation for Release 12.4Documentation Organization for Cisco IOS Release 12.4
xxiiCisco IOS LAN Switching Configuration Guide
Cisco IOS NetFlow Configuration Guide, Release 12.4
Cisco IOS NetFlow Command Reference, Release 12.4
The configuration guide is a task-oriented guide to NetFlow features, including configuring NetFlow to analyze network traffic data, configuring NetFlow aggregation caches and export features, and configuring Simple Network Management Protocol (SNMP) and NetFlow MIB features. The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS Network Management Configuration Guide, Release 12.4
Cisco IOS Network Management Command Reference, Release 12.4
The configuration guide is a task-oriented guide to network management features, including performing basic system management, performing troubleshooting and fault management, configuring Cisco Discovery Protocol, configuring Cisco Networking Services (CNS), configuring DistributedDirector, and configuring Simple Network Management Protocol (SNMP). The command reference provides detailed information about the commands used in the configuration guide.
Voice
Cisco IOS Voice Configuration Library, Release 12.4
Cisco IOS Voice Command Reference, Release 12.4
The configuration library is a task-oriented collection of configuration guides, application guides, a troubleshooting guide, feature documents, a library preface, a voice glossary, and more. It also covers Cisco IOS support for voice call control protocols, interoperability, physical and virtual interface management, and troubleshooting. In addition, the library includes documentation for IP telephony applications. The command reference provides detailed information about the commands used in the configuration library.
Wireless/Mobility
Cisco IOS Mobile Wireless Gateway GPRS Support Node Configuration Guide, Release 12.4
Cisco IOS Mobile Wireless Gateway GPRS Support Node Command Reference, Release 12.4
The configuration guide is a task-oriented guide to understanding and configuring a Cisco IOS Gateway GPRS Support Node (GGSN) in a 2.5G General Packet Radio Service (GPRS) and 3G Universal Mobile Telecommunication System (UMTS) network. The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS Mobile Wireless Home Agent Configuration Guide, Release 12.4
Cisco IOS Mobile Wireless Home Agent Command Reference, Release 12.4
The configuration guide is a task-oriented guide to understanding and configuring the Cisco Mobile Wireless Home Agent, which is an anchor point for mobile terminals for which Mobile IP or Proxy Mobile IP services are provided. The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS Mobile Wireless Packet Data Serving Node Configuration Guide, Release 12.4
Cisco IOS Mobile Wireless Packet Data Serving Node Command Reference, Release 12.4
The configuration guide is a task-oriented guide to understanding and configuring the Cisco Packet Data Serving Node (PDSN), a wireless gateway between the mobile infrastructure and standard IP networks that enables packet data services in a Code Division Multiple Access (CDMA) environment. The command reference provides detailed information about the commands used in the configuration guide.
Table 1 Cisco IOS Release 12.4 Configuration Guides and Command References (continued)
Configuration Guide and Command Reference Titles
Description
About Cisco IOS Software Documentation for Release 12.4Documentation Organization for Cisco IOS Release 12.4
xxiiiCisco IOS LAN Switching Configuration Guide
Cisco IOS Mobile Wireless Radio Access Networking Configuration Guide, Release 12.4
Cisco IOS Mobile Wireless Radio Access Networking Command Reference, Release 12.4
The configuration guide is a task-oriented guide to understanding and configuring Cisco IOS Radio Access Network products. The command reference provides detailed information about the commands used in the configuration guide.
Long Reach Ethernet (LRE) and Digital Subscriber Line (xDSL)
Cisco IOS Broadband and DSL Configuration Guide, Release 12.4
Cisco IOS Broadband and DSL Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring broadband access aggregation and digital subscriber line features. The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS Service Selection GatewayConfiguration Guide, Release 12.4
Cisco IOS Service Selection Gateway Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring Service Selection Gateway (SSG) features, including subscriber authentication, service access, and accounting. The command reference provides detailed information about the commands used in the configuration guide.
Dial—Access
Cisco IOS Dial Technologies Configuration Guide, Release 12.4
Cisco IOS Dial Technologies Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring lines, modems, and ISDN services. This guide also contains information about configuring dialup solutions, including solutions for remote sites dialing in to a central office, Internet service providers (ISPs), ISP customers at home offices, enterprise WAN system administrators implementing dial-on-demand routing, and other corporate environments. The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS VPDN Configuration Guide, Release 12.4
Cisco IOS VPDN Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring Virtual Private Dialup Networks (VPDNs), including information about Layer 2 tunneling protocols, client-initiated VPDN tunneling, NAS-initiated VPDN tunneling, and multihop VPDN. The command reference provides detailed information about the commands used in the configuration guide.
Asynchronous Transfer Mode (ATM)
Cisco IOS Asynchronous Transfer Mode Configuration Guide, Release 12.4
Cisco IOS Asynchronous Transfer Mode Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring Asynchronous Transfer Mode (ATM), including WAN ATM, LAN ATM, and multiprotocol over ATM (MPOA). The command reference provides detailed information about the commands used in the configuration guide.
WAN
Cisco IOS Wide-Area Networking Configuration Guide, Release 12.4
Cisco IOS Wide-Area Networking Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring wide-area network (WAN) features, including Layer 2 Tunneling Protocol Version 3 (L2TPv3); Frame Relay; Link Access Procedure, Balanced (LAPB); and X.25. The command reference provides detailed information about the commands used in the configuration guide.
Table 1 Cisco IOS Release 12.4 Configuration Guides and Command References (continued)
Configuration Guide and Command Reference Titles
Description
About Cisco IOS Software Documentation for Release 12.4Documentation Organization for Cisco IOS Release 12.4
xxivCisco IOS LAN Switching Configuration Guide
System Management
Cisco IOS Configuration Fundamentals Configuration Guide, Release 12.4
Cisco IOS Configuration Fundamentals Command Reference, Release 12.4
The configuration guide is a task-oriented guide to using Cisco IOS software to configure and maintain Cisco routers and access servers, including information about using the Cisco IOS command-line interface (CLI), loading and maintaining system images, using the Cisco IOS file system, using the Cisco IOS Web browser user interface (UI), and configuring basic file transfer services. The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS Interface and Hardware Component Configuration Guide, Release 12.4
Cisco IOS Interface and Hardware Component Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring and managing interfaces and hardware components, including dial shelves, LAN interfaces, logical interfaces, serial interfaces, and virtual interfaces. The command reference provides detailed information about the commands used in the configuration guide.
IBM Technologies
Cisco IOS Bridging and IBM Networking Configuration Guide, Release 12.4
Cisco IOS Bridging Command Reference, Release 12.4
Cisco IOS IBM Networking Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring:
• Bridging features, including transparent and source-route transparent (SRT) bridging, source-route bridging (SRB), Token Ring Inter-Switch Link (TRISL), and Token Ring Route Switch Module (TRRSM).
• IBM network features, including data-link switching plus (DLSw+), serial tunnel (STUN), and block serial tunnel (BSTUN); Logical Link Control, type 2 (LLC2), and Synchronous Data Link Control (SDLC); IBM Network Media Translation, including SDLC Logical Link Control (SDLLC) and Qualified Logical Link Control (QLLC); downstream physical unit (DSPU), Systems Network Architecture (SNA) service point, SNA Frame Relay Access, Advanced Peer-to-Peer Networking (APPN), native client interface architecture (NCIA) client/server topologies, and IBM Channel Attach.
The two command references provide detailed information about the commands used in the configuration guide.
Additional and Legacy Protocols
Cisco IOS AppleTalk Configuration Guide, Release 12.4
Cisco IOS AppleTalkCommand Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring the AppleTalk protocol. The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS DECnet Configuration Guide, Release 12.4
Cisco IOS DECnet Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring the DECnet protocol. The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS ISO CLNS Configuration Guide, Release 12.4
Cisco IOS ISO CLNS Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring International Organization for Standardization (ISO) Connectionless Network Service (CLNS). The command reference provides detailed information about the commands used in the configuration guide.
Table 1 Cisco IOS Release 12.4 Configuration Guides and Command References (continued)
Configuration Guide and Command Reference Titles
Description
About Cisco IOS Software Documentation for Release 12.4Documentation Organization for Cisco IOS Release 12.4
xxvCisco IOS LAN Switching Configuration Guide
Table 2 lists the documents and resources that support the Cisco IOS Release 12.4 software configuration guides and command references.
Cisco IOS Novell IPX Configuration Guide, Release 12.4
Cisco IOS Novell IPX Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring the Novell Internetwork Packet Exchange (IPX) protocol. The command reference provides detailed information about the commands used in the configuration guide.
Cisco IOS Terminal Services Configuration Guide, Release 12.4
Cisco IOS Terminal Services Command Reference, Release 12.4
The configuration guide is a task-oriented guide to configuring terminal services, including DEC, local-area transport (LAT), and X.25 packet assembler/disassembler (PAD). The command reference provides detailed information about the commands used in the configuration guide.
Table 1 Cisco IOS Release 12.4 Configuration Guides and Command References (continued)
Configuration Guide and Command Reference Titles
Description
Table 2 Cisco IOS Release 12.4 Supporting Documents and Resources
Document Title Description
Cisco IOS Master Commands List, Release 12.4
An alphabetical listing of all the commands documented in the Cisco IOS Release 12.4 command references.
Cisco IOS New, Modified, Replaced, and Removed Commands, Release 12.4
A listing of all the new, modified, replaced and removed commands since Cisco IOS Release 12.3, grouped by Release 12.3T maintenance release and ordered alphabetically within each group.
Cisco IOS New and Modified Commands, Release 12.3
A listing of all the new, modified, and replaced commands since Cisco IOS Release 12.2, grouped by Release 12.2T maintenance release and ordered alphabetically within each group.
Cisco IOS System Messages, Volume 1 of 2
Cisco IOS System Messages, Volume 2 of 2
Listings and descriptions of Cisco IOS system messages. Not all system messages indicate problems with your system. Some are purely informational, and others may help diagnose problems with communications lines, internal hardware, or the system software.
Cisco IOS Debug Command Reference, Release 12.4
An alphabetical listing of the debug commands and their descriptions. Documentation for each command includes a brief description of its use, command syntax, and usage guidelines.
Release Notes, Release 12.4 A description of general release information, including information about supported platforms, feature sets, platform-specific notes, and Cisco IOS software defects.
Internetworking Terms and Acronyms Compilation and definitions of the terms and acronyms used in the internetworking industry.
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Document ConventionsWithin Cisco IOS software documentation, the term router is generally used to refer to a variety of Cisco products (for example, routers, access servers, and switches). Routers, access servers, and other networking devices that support Cisco IOS software are shown interchangeably within examples. These products are used only for illustrative purposes; that is, an example that shows one product does not necessarily indicate that other products are not supported.
The Cisco IOS documentation set uses the following conventions:
Command syntax descriptions use the following conventions:
RFCs RFCs are standards documents maintained by the Internet Engineering Task Force (IETF). Cisco IOS software documentation references supported RFCs when applicable. The full text of referenced RFCs may be obtained at the following URL:
http://www.rfc-editor.org/
MIBs MIBs are used for network monitoring. To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
http://www.cisco.com/go/mibs
Table 2 Cisco IOS Release 12.4 Supporting Documents and Resources (continued)
Document Title Description
Convention Description
^ or Ctrl The ^ and Ctrl symbols represent the Control key. For example, the key combination ^D or Ctrl-D means hold down the Control key while you press the D key. Keys are indicated in capital letters but are not case sensitive.
string A string is a nonquoted set of characters shown in italics. For example, when setting an SNMP community string to public, do not use quotation marks around the string or the string will include the quotation marks.
Convention Description
bold Bold text indicates commands and keywords that you enter literally as shown.
italics Italic text indicates arguments for which you supply values.
[x] Square brackets enclose an optional element (keyword or argument).
| A vertical line indicates a choice within an optional or required set of keywords or arguments.
[x | y] Square brackets enclosing keywords or arguments separated by a vertical line indicate an optional choice.
{x | y} Braces enclosing keywords or arguments separated by a vertical line indicate a required choice.
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Nested sets of square brackets or braces indicate optional or required choices within optional or required elements. For example:
Examples use the following conventions:
The following conventions are used to attract the attention of the reader:
Caution Means reader be careful. In this situation, you might do something that could result in equipment damage or loss of data.
Note Means reader take note. Notes contain suggestions or references to material not covered in the manual.
Timesaver Means the described action saves time. You can save time by performing the action described in the paragraph.
Obtaining DocumentationCisco documentation and additional literature are available on Cisco.com. Cisco also provides several ways to obtain technical assistance and other technical resources. These sections explain how to obtain technical information from Cisco Systems.
Cisco.comYou can access the most current Cisco documentation and technical support at this URL:
http://www.cisco.com/techsupport
Convention Description
[x {y | z}] Braces and a vertical line within square brackets indicate a required choice within an optional element.
Convention Descriptionscreen Examples of information displayed on the screen are set in Courier font.
bold screen Examples of text that you must enter are set in Courier bold font.
< > Angle brackets enclose text that is not printed to the screen, such as passwords, and are used in contexts in which the italic document convention is not available, such as ASCII text.
! An exclamation point at the beginning of a line indicates a comment line. (Exclamation points are also displayed by the Cisco IOS software for certain processes.)
[ ] Square brackets enclose default responses to system prompts.
About Cisco IOS Software Documentation for Release 12.4Documentation Feedback
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You can access the Cisco website at this URL:
http://www.cisco.com
You can access international Cisco websites at this URL:
http://www.cisco.com/public/countries_languages.shtml
Product Documentation DVDCisco documentation and additional literature are available in the Product Documentation DVD package, which may have shipped with your product. The Product Documentation DVD is updated regularly and may be more current than printed documentation.
The Product Documentation DVD is a comprehensive library of technical product documentation on portable media. The DVD enables you to access multiple versions of hardware and software installation, configuration, and command guides for Cisco products and to view technical documentation in HTML. With the DVD, you have access to the same documentation that is found on the Cisco website without being connected to the Internet. Certain products also have .pdf versions of the documentation available.
The Product Documentation DVD is available as a single unit or as a subscription. Registered Cisco.com users (Cisco direct customers) can order a Product Documentation DVD (product number DOC-DOCDVD=) from Cisco Marketplace at this URL:
http://www.cisco.com/go/marketplace/
Ordering DocumentationBeginning June 30, 2005, registered Cisco.com users may order Cisco documentation at the Product Documentation Store in the Cisco Marketplace at this URL:
http://www.cisco.com/go/marketplace/
Nonregistered Cisco.com users can order technical documentation from 8:00 a.m. to 5:00 p.m. (0800 to 1700) PDT by calling 1 866 463-3487 in the United States and Canada, or elsewhere by calling 011 408 519-5055. You can also order documentation by e-mail at [email protected] or by fax at 1 408 519-5001 in the United States and Canada, or elsewhere at 011 408 519-5001.
Documentation FeedbackYou can rate and provide feedback about Cisco technical documents by completing the online feedback form that appears with the technical documents on Cisco.com.
You can send comments about Cisco documentation to [email protected].
You can submit comments by using the response card (if present) behind the front cover of your document or by writing to the following address:
Cisco SystemsAttn: Customer Document Ordering170 West Tasman DriveSan Jose, CA 95134-9883
We appreciate your comments.
About Cisco IOS Software Documentation for Release 12.4Cisco Product Security Overview
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Cisco Product Security OverviewCisco provides a free online Security Vulnerability Policy portal at this URL:
http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html
From this site, you can perform these tasks:
• Report security vulnerabilities in Cisco products.
• Obtain assistance with security incidents that involve Cisco products.
• Register to receive security information from Cisco.
A current list of security advisories and notices for Cisco products is available at this URL:
http://www.cisco.com/go/psirt
If you prefer to see advisories and notices as they are updated in real time, you can access a Product Security Incident Response Team Really Simple Syndication (PSIRT RSS) feed from this URL:
http://www.cisco.com/en/US/products/products_psirt_rss_feed.html
Reporting Security Problems in Cisco ProductsCisco is committed to delivering secure products. We test our products internally before we release them, and we strive to correct all vulnerabilities quickly. If you think that you might have identified a vulnerability in a Cisco product, contact PSIRT:
• Emergencies— [email protected]
An emergency is either a condition in which a system is under active attack or a condition for which a severe and urgent security vulnerability should be reported. All other conditions are considered nonemergencies.
• Nonemergencies— [email protected]
In an emergency, you can also reach PSIRT by telephone:
• 1 877 228-7302
• 1 408 525-6532
Tip We encourage you to use Pretty Good Privacy (PGP) or a compatible product to encrypt any sensitive information that you send to Cisco. PSIRT can work from encrypted information that is compatible with PGP versions 2.x through 8.x.
Never use a revoked or an expired encryption key. The correct public key to use in your correspondence with PSIRT is the one linked in the Contact Summary section of the Security Vulnerability Policy page at this URL:
http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html
The link on this page has the current PGP key ID in use.
About Cisco IOS Software Documentation for Release 12.4Obtaining Technical Assistance
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Obtaining Technical AssistanceCisco Technical Support provides 24-hour-a-day award-winning technical assistance. The Cisco Technical Support & Documentation website on Cisco.com features extensive online support resources. In addition, if you have a valid Cisco service contract, Cisco Technical Assistance Center (TAC) engineers provide telephone support. If you do not have a valid Cisco service contract, contact your reseller.
Cisco Technical Support & Documentation WebsiteThe Cisco Technical Support & Documentation website provides online documents and tools for troubleshooting and resolving technical issues with Cisco products and technologies. The website is available 24 hours a day, at this URL:
http://www.cisco.com/techsupport
Access to all tools on the Cisco Technical Support & Documentation website requires a Cisco.com user ID and password. If you have a valid service contract but do not have a user ID or password, you can register at this URL:
http://tools.cisco.com/RPF/register/register.do
Note Use the Cisco Product Identification (CPI) tool to locate your product serial number before submitting a web or phone request for service. You can access the CPI tool from the Cisco Technical Support & Documentation website by clicking the Tools & Resources link. Choose Cisco Product Identification Tool from the Alphabetical Index drop-down list, or click the Cisco Product Identification Tool link under Alerts & RMAs. The CPI tool offers three search options: by product ID or model name; by tree view; or for certain products, by copying and pasting show command output. Search results show an illustration of your product with the serial number label location highlighted. Locate the serial number label on your product and record the information before placing a service call.
Submitting a Service RequestUsing the online TAC Service Request Tool is the fastest way to open S3 and S4 service requests. (S3 and S4 service requests are those in which your network is minimally impaired or for which you require product information.) After you describe your situation, the TAC Service Request Tool provides recommended solutions. If your issue is not resolved using the recommended resources, your service request is assigned to a Cisco engineer. The TAC Service Request Tool is located at this URL:
http://www.cisco.com/techsupport/servicerequest
For S1 or S2 service requests or if you do not have Internet access, contact the Cisco TAC by telephone. (S1 or S2 service requests are those in which your production network is down or severely degraded.) Cisco engineers are assigned immediately to S1 and S2 service requests to help keep your business operations running smoothly.
To open a service request by telephone, use one of the following numbers:
Asia-Pacific: +61 2 8446 7411 (Australia: 1 800 805 227)EMEA: +32 2 704 55 55USA: 1 800 553-2447
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For a complete list of Cisco TAC contacts, go to this URL:
http://www.cisco.com/techsupport/contacts
Definitions of Service Request SeverityTo ensure that all service requests are reported in a standard format, Cisco has established severity definitions.
Severity 1 (S1)—Your network is “down,” or there is a critical impact to your business operations. You and Cisco will commit all necessary resources around the clock to resolve the situation.
Severity 2 (S2)—Operation of an existing network is severely degraded, or significant aspects of your business operation are negatively affected by inadequate performance of Cisco products. You and Cisco will commit full-time resources during normal business hours to resolve the situation.
Severity 3 (S3)—Operational performance of your network is impaired, but most business operations remain functional. You and Cisco will commit resources during normal business hours to restore service to satisfactory levels.
Severity 4 (S4)—You require information or assistance with Cisco product capabilities, installation, or configuration. There is little or no effect on your business operations.
Obtaining Additional Publications and InformationInformation about Cisco products, technologies, and network solutions is available from various online and printed sources.
• Cisco Marketplace provides a variety of Cisco books, reference guides, documentation, and logo merchandise. Visit Cisco Marketplace, the company store, at this URL:
http://www.cisco.com/go/marketplace/
• Cisco Press publishes a wide range of general networking, training and certification titles. Both new and experienced users will benefit from these publications. For current Cisco Press titles and other information, go to Cisco Press at this URL:
http://www.ciscopress.com
• Packet magazine is the Cisco Systems technical user magazine for maximizing Internet and networking investments. Each quarter, Packet delivers coverage of the latest industry trends, technology breakthroughs, and Cisco products and solutions, as well as network deployment and troubleshooting tips, configuration examples, customer case studies, certification and training information, and links to scores of in-depth online resources. You can access Packet magazine at this URL:
http://www.cisco.com/packet
• iQ Magazine is the quarterly publication from Cisco Systems designed to help growing companies learn how they can use technology to increase revenue, streamline their business, and expand services. The publication identifies the challenges facing these companies and the technologies to help solve them, using real-world case studies and business strategies to help readers make sound technology investment decisions. You can access iQ Magazine at this URL:
http://www.cisco.com/go/iqmagazine
or view the digital edition at this URL:
http://ciscoiq.texterity.com/ciscoiq/sample/
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• Internet Protocol Journal is a quarterly journal published by Cisco Systems for engineering professionals involved in designing, developing, and operating public and private internets and intranets. You can access the Internet Protocol Journal at this URL:
http://www.cisco.com/ipj
• Networking products offered by Cisco Systems, as well as customer support services, can be obtained at this URL:
http://www.cisco.com/en/US/products/index.html
• Networking Professionals Connection is an interactive website for networking professionals to share questions, suggestions, and information about networking products and technologies with Cisco experts and other networking professionals. Join a discussion at this URL:
http://www.cisco.com/discuss/networking
• World-class networking training is available from Cisco. You can view current offerings at this URL:
http://www.cisco.com/en/US/learning/index.html
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Using Cisco IOS Software for Release 12.4
This chapter provides tips for understanding and configuring Cisco IOS software using the command-line interface (CLI). It contains the following sections:
• Understanding Command Modes, page xxxiii
• Getting Help, page xxxiv
• Using the no and default Forms of Commands, page xxxviii
• Saving Configuration Changes, page xxxviii
• Filtering Output from the show and more Commands, page xxxix
• Finding Additional Feature Support Information, page xxxix
For an overview of Cisco IOS software configuration, see the Cisco IOS Configuration Fundamentals Configuration Guide.
For information on the conventions used in the Cisco IOS software documentation set, see the “About Cisco IOS Software Documentation for Release 12.4” chapter.
Understanding Command ModesYou use the CLI to access Cisco IOS software. Because the CLI is divided into many different modes, the commands available to you at any given time depend on the mode that you are currently in. Entering a question mark (?) at the CLI prompt allows you to obtain a list of commands available for each command mode.
When you log in to a Cisco device, the device is initially in user EXEC mode. User EXEC mode contains only a limited subset of commands. To have access to all commands, you must enter privileged EXEC mode by entering the enable command and a password (when required). From privileged EXEC mode you have access to both user EXEC and privileged EXEC commands. Most EXEC commands are used independently to observe status or to perform a specific function. For example, show commands are used to display important status information, and clear commands allow you to reset counters or interfaces. The EXEC commands are not saved when the software reboots.
Configuration modes allow you to make changes to the running configuration. If you later save the running configuration to the startup configuration, these changed commands are stored when the software is rebooted. To enter specific configuration modes, you must start at global configuration mode. From global configuration mode, you can enter interface configuration mode and a variety of other modes, such as protocol-specific modes.
Using Cisco IOS Software for Release 12.4Getting Help
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ROM monitor mode is a separate mode used when the Cisco IOS software cannot load properly. If a valid software image is not found when the software boots or if the configuration file is corrupted at startup, the software might enter ROM monitor mode.
Table 1 describes how to access and exit various common command modes of the Cisco IOS software. It also shows examples of the prompts displayed for each mode.
For more information on command modes, see the “Using the Cisco IOS Command-Line Interface” chapter in the Cisco IOS Configuration Fundamentals Configuration Guide.
Getting HelpEntering a question mark (?) at the CLI prompt displays a list of commands available for each command mode. You can also get a list of keywords and arguments associated with any command by using the context-sensitive help feature.
To get help specific to a command mode, a command, a keyword, or an argument, use one of the following commands:
Table 1 Accessing and Exiting Command Modes
Command Mode
Access Method Prompt Exit Method
User EXEC Log in. Router> Use the logout command.
Privileged EXEC
From user EXEC mode, use the enable command.
Router# To return to user EXEC mode, use the disable command.
Global configuration
From privileged EXEC mode, use the configure terminal command.
Router(config)# To return to privileged EXEC mode from global configuration mode, use the exit or end command.
Interface configuration
From global configuration mode, specify an interface using an interface command.
Router(config-if)# To return to global configuration mode, use the exit command.
To return to privileged EXEC mode, use the end command.
ROM monitor From privileged EXEC mode, use the reload command. Press the Break key during the first 60 seconds while the system is booting.
> To exit ROM monitor mode, use the continue command.
Command Purpose
help Provides a brief description of the help system in any command mode.
abbreviated-command-entry? Provides a list of commands that begin with a particular character string. (No space between command and question mark.)
abbreviated-command-entry<Tab> Completes a partial command name.
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Example: How to Find Command OptionsThis section provides an example of how to display syntax for a command. The syntax can consist of optional or required keywords and arguments. To display keywords and arguments for a command, enter a question mark (?) at the configuration prompt or after entering part of a command followed by a space. The Cisco IOS software displays a list and brief description of available keywords and arguments. For example, if you were in global configuration mode and wanted to see all the keywords or arguments for the arap command, you would type arap ?.
The <cr> symbol in command help output stands for “carriage return.” On older keyboards, the carriage return key is the Return key. On most modern keyboards, the carriage return key is the Enter key. The <cr> symbol at the end of command help output indicates that you have the option to press Enter to complete the command and that the arguments and keywords in the list preceding the <cr> symbol are optional. The <cr> symbol by itself indicates that no more arguments or keywords are available and that you must press Enter to complete the command.
Table 2 shows examples of how you can use the question mark (?) to assist you in entering commands. The table steps you through configuring an IP address on a serial interface on a Cisco 7206 router that is running Cisco IOS Release 12.0(3).
? Lists all commands available for a particular command mode.
command ? Lists the keywords or arguments that you must enter next on the command line. (Space between command and question mark.)
Command Purpose
Table 2 How to Find Command Options
Command Comment
Router> enablePassword: <password>Router#
Enter the enable command and password to access privileged EXEC commands. You are in privileged EXEC mode when the prompt changes to Router#.
Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)#
Enter the configure terminal privileged EXEC command to enter global configuration mode. You are in global configuration mode when the prompt changes to Router(config)#.
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Router(config)# interface serial ?<0-6> Serial interface number
Router(config)# interface serial 4 ?/
Router(config)# interface serial 4/ ?<0-3> Serial interface number
Router(config)# interface serial 4/0 ?<cr>Router(config)# interface serial 4/0Router(config-if)#
Enter interface configuration mode by specifying the serial interface that you want to configure using the interface serial global configuration command.
Enter ? to display what you must enter next on the command line. In this example, you must enter the serial interface slot number and port number, separated by a forward slash.
When the <cr> symbol is displayed, you can press Enter to complete the command.
You are in interface configuration mode when the prompt changes to Router(config-if)#.
Router(config-if)# ?Interface configuration commands:
.
.
.ip Interface Internet Protocol config commandskeepalive Enable keepalivelan-name LAN Name commandllc2 LLC2 Interface Subcommandsload-interval Specify interval for load calculation for an
interfacelocaddr-priority Assign a priority grouplogging Configure logging for interfaceloopback Configure internal loopback on an interfacemac-address Manually set interface MAC addressmls mls router sub/interface commandsmpoa MPOA interface configuration commandsmtu Set the interface Maximum Transmission Unit (MTU)netbios Use a defined NETBIOS access list or enable
name-cachingno Negate a command or set its defaultsnrzi-encoding Enable use of NRZI encodingntp Configure NTP...
Router(config-if)#
Enter ? to display a list of all the interface configuration commands available for the serial interface. This example shows only some of the available interface configuration commands.
Table 2 How to Find Command Options (continued)
Command Comment
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Router(config-if)# ip ?Interface IP configuration subcommands:
access-group Specify access control for packetsaccounting Enable IP accounting on this interfaceaddress Set the IP address of an interfaceauthentication authentication subcommandsbandwidth-percent Set EIGRP bandwidth limitbroadcast-address Set the broadcast address of an interfacecgmp Enable/disable CGMPdirected-broadcast Enable forwarding of directed broadcastsdvmrp DVMRP interface commandshello-interval Configures IP-EIGRP hello intervalhelper-address Specify a destination address for UDP broadcastshold-time Configures IP-EIGRP hold time...
Router(config-if)# ip
Enter the command that you want to configure for the interface. This example uses the ip command.
Enter ? to display what you must enter next on the command line. This example shows only some of the available interface IP configuration commands.
Router(config-if)# ip address ?A.B.C.D IP addressnegotiated IP Address negotiated over PPP
Router(config-if)# ip address
Enter the command that you want to configure for the interface. This example uses the ip address command.
Enter ? to display what you must enter next on the command line. In this example, you must enter an IP address or the negotiated keyword.
A carriage return (<cr>) is not displayed; therefore, you must enter additional keywords or arguments to complete the command.
Router(config-if)# ip address 172.16.0.1 ?A.B.C.D IP subnet mask
Router(config-if)# ip address 172.16.0.1
Enter the keyword or argument that you want to use. This example uses the 172.16.0.1 IP address.
Enter ? to display what you must enter next on the command line. In this example, you must enter an IP subnet mask.
A <cr> is not displayed; therefore, you must enter additional keywords or arguments to complete the command.
Table 2 How to Find Command Options (continued)
Command Comment
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Using the no and default Forms of CommandsAlmost every configuration command has a no form. In general, use the no form to disable a function. Use the command without the no keyword to reenable a disabled function or to enable a function that is disabled by default. For example, IP routing is enabled by default. To disable IP routing, use the no ip routing command; to reenable IP routing, use the ip routing command. The Cisco IOS software command reference publications provide the complete syntax for the configuration commands and describe what the no form of a command does.
Configuration commands can also have a default form, which returns the command settings to the default values. Most commands are disabled by default, so in such cases using the default form has the same result as using the no form of the command. However, some commands are enabled by default and have variables set to certain default values. In these cases, the default form of the command enables the command and sets the variables to their default values. The Cisco IOS software command reference publications describe the effect of the default form of a command if the command functions differently than the no form.
Saving Configuration ChangesUse the copy system:running-config nvram:startup-config command or the copy running-config startup-config command to save your configuration changes to the startup configuration so that the changes will not be lost if the software reloads or a power outage occurs. For example:
Router# copy system:running-config nvram:startup-configBuilding configuration...
It might take a minute or two to save the configuration. After the configuration has been saved, the following output appears:
[OK]Router#
On most platforms, this task saves the configuration to NVRAM. On the Class A flash file system platforms, this task saves the configuration to the location specified by the CONFIG_FILE environment variable. The CONFIG_FILE variable defaults to NVRAM.
Router(config-if)# ip address 172.16.0.1 255.255.255.0 ?secondary Make this IP address a secondary address<cr>
Router(config-if)# ip address 172.16.0.1 255.255.255.0
Enter the IP subnet mask. This example uses the 255.255.255.0 IP subnet mask.
Enter ? to display what you must enter next on the command line. In this example, you can enter the secondary keyword, or you can press Enter.
A <cr> is displayed; you can press Enter to complete the command, or you can enter another keyword.
Router(config-if)# ip address 172.16.0.1 255.255.255.0Router(config-if)#
In this example, Enter is pressed to complete the command.
Table 2 How to Find Command Options (continued)
Command Comment
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Filtering Output from the show and more CommandsYou can search and filter the output of show and more commands. This functionality is useful if you need to sort through large amounts of output or if you want to exclude output that you need not see.
To use this functionality, enter a show or more command followed by the “pipe” character (|); one of the keywords begin, include, or exclude; and a regular expression on which you want to search or filter (the expression is case-sensitive):
command | {begin | include | exclude} regular-expression
The output matches certain lines of information in the configuration file. The following example illustrates how to use output modifiers with the show interface command when you want the output to include only lines in which the expression “protocol” appears:
Router# show interface | include protocol
FastEthernet0/0 is up, line protocol is upSerial4/0 is up, line protocol is upSerial4/1 is up, line protocol is upSerial4/2 is administratively down, line protocol is downSerial4/3 is administratively down, line protocol is down
For more information on the search and filter functionality, see the “Using the Cisco IOS Command-Line Interface” chapter in the Cisco IOS Configuration Fundamentals Configuration Guide.
Finding Additional Feature Support InformationIf you want to use a specific Cisco IOS software feature, you will need to determine in which Cisco IOS software images that feature is supported. Feature support in Cisco IOS software images depends on three main factors: the software version (called the “Release”), the hardware model (the “Platform” or “Series”), and the “Feature Set” (collection of specific features designed for a certain network environment). Although the Cisco IOS software documentation set documents feature support information for Release 12.4 as a whole, it does not generally provide specific hardware and feature set information.
To determine the correct combination of Release (software version), Platform (hardware version), and Feature Set needed to run a particular feature (or any combination of features), use Feature Navigator.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Software features may also have additional limitations or restrictions. For example, a minimum amount of system memory may be required. Or there may be known issues for features on certain platforms that have not yet been resolved (called “Caveats”). For the latest information about these limitations, see the release notes for the appropriate Cisco IOS software release. Release notes provide detailed installation instructions, new feature descriptions, system requirements, limitations and restrictions, caveats, and troubleshooting information for a particular software release.
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Part 1: Virtual LANs
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Virtual LANS Features Roadmap
This roadmap lists the features documented in the Virtual LANs modules in which they appear.
Roadmap History
This roadmap was first published April 20, 2006 and last updated on April 20, 2006.
Features and Release Support
Table 1 lists Virtual LANs feature support for the following Cisco IOS software release trains:
• Cisco IOS Releases 12.0, 12.1, 12.2, 12.3, and 12.3T
Only features that were introduced or modified in Cisco IOS Release 12.0 (1) or a later release appear in the table. Not all features may be supported in your Cisco IOS software release.
Cisco IOS software images are specific to a Cisco IOS software release, a feature set, and a platform. Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Note Table 3 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.
Virtual LANS Features Roadmap
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Table 3 Supported Network Address Translation Features
Release Feature Name Feature Description Where Documented
Cisco IOS Releases 12.0, 12.1, 12.2, 12.3, and 12.3T
12.0(7)XE
12.1(5)T
12.2(2)DD
12.2(4)B
12.2(8)T
12.2(13)T
VLAN Range Using the VLAN Range feature, you can group VLAN subinterfaces together so that any command entered in a group applies to every subinterface within the group. This capability simplifies configurations and reduces command parsing.
Configuring Routing Between VLANs
• Configuring a Range of VLAN Subinterfaces, page 19
Configuring Routing Between VLANs with IEEE 802.1Q Encapsulation
The IEEE 802.1Q protocol is used to interconnect multiple switches and routers, and for defining VLAN topologies. The IEEE 802.1Q standard is extremely restrictive to untagged frames. The standard provides only a per-port VLANs solution for untagged frames. For example, assigning untagged frames to VLANs takes into consideration only the port from which they have been received. Each port has a parameter called a permanent virtual identification (Native VLAN) that specifies the VLAN assigned to receive untagged frames.
Configuring Routing Between VLANs
• Configuring Routing Between VLANs with IEEE 802.1Q Encapsulation
Configuring Routing Between VLANs with Inter-Switch Link Encapsulation
ISL is a Cisco protocol for interconnecting multiple switches and maintaining VLAN information as traffic goes between switches. ISL provides VLAN capabilities while maintaining full wire speed performance on Fast Ethernet links in full- or half-duplex mode. ISL operates in a point-to-point environment and will support up to 1000 VLANs. You can define virtually as many logical networks as are necessary for your environment.
Configuring Routing Between VLANs
• Configuring Routing Between VLANs with Inter-Switch Link Encapsulation
Configuring Routing Between VLANs with IEEE 802.10 Encapsulation
AppleTalk can be routed over VLAN subinterfaces using the ISL or IEEE 802.10 VLANs feature that provides full-feature Cisco IOS software AppleTalk support on a per-VLAN basis, allowing standard AppleTalk capabilities to be configured on VLANs.
Configuring Routing Between VLANs
• Configuring Routing Between VLANs with IEEE 802.10 Encapsulation
Virtual LANS Features Roadmap
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12.3(8)T4 Cisco HWIC-4ESW and HWIC-D-9ESW EtherSwitch Interface Cards
Cisco EtherSwitch HWICs are 10/100BASE-T Layer 2 Ethernet switches with Layer 3 routing capability. (Layer 3 routing is forwarded to the host and is not actually performed at the switch.) Traffic between different VLANs on a switch is routed through the router platform. Any one port on a Cisco EtherSwitch HWIC may be configured as a stacking port to link to another Cisco EtherSwitch HWIC or EtherSwitch network module in the same system. An optional power module can also be added to provide inline power for IP telephones. The HWIC-D-9ESW HWIC requires a double-wide card slot.
Cisco HWIC-4ESW and HWIC-D-9ESW EtherSwitch Interface Cards
12.2(2)XT
12.2(8)T
12.2(15)ZJ
12.3(4)T
EtherSwitch Module The EtherSwitch network module is supported on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers. The EtherSwitch network module is a modular, high-density voice network module that provides Layer 2 switching across Ethernet ports. The EtherSwitch network module has sixteen 10/100 switched Ethernet ports with integrated inline power and QoS features that are designed to extend Cisco AVVID-based voice-over-IP (VoIP) networks to small branch offices.
EtherSwitch Network Module
12.3(2)XC Managed VLAN Switch The Managed LAN Switch feature enables the control of the four switch ports in Cisco 831, 836, and 837 routers. Each switch port is associated with a Fast Ethernet interface.
Managed LAN Switch
12.3(7)T
12.3(7)XI1
IEEE 802.1Q-in-Q VLAN Tag Termination
Encapsulating IEEE 802.1Q VLAN tags within 802.1Q enables service providers to use a single VLAN to support customers who have multiple VLANs. The IEEE 802.1Q-in-Q VLAN Tag Termination feature on the subinterface level preserves VLAN IDs and keeps traffic in different customer VLANs segregated.
Configuring Routing Between VLANs
• Configuring IEEE 802.1Q-in-Q VLAN Tag Termination, page 45
Table 3 Supported Network Address Translation Features (continued)
Release Feature Name Feature Description Where Documented
Virtual LANS Features Roadmap
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Configuring Routing Between VLANs
First Published: March 15, 2006Last Updated: March 15, 2006
This module provides an overview of VLANs. It describes the encapsulation protocols used for routing between VLANs and provides some basic information about designing VLANs. This module contains tasks for configuring routing between VLANS.
Finding Feature Information in This Module
Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the “Feature Information for Routing Between VLANs” section on page 76.
Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Contents• Information About Routing Between VLANs, page 7
• How to Configure Routing Between VLANS, page 18
• Configuration Examples for Configuring Routing Between VLANs, page 56
• Additional References, page 74
• Feature Information for Routing Between VLANs, page 76
Information About Routing Between VLANsThis module describes routing between VLANs. It contains the following sections:
• Virtual Local Area Network Definition, page 8
• VLAN Performance, page 10
• VLAN Colors, page 14
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• Implementing VLANS, page 15
• Communication Between VLANs, page 15
• VLAN Interoperability, page 17
• Designing Switched VLANs, page 18
Virtual Local Area Network DefinitionA virtual local area network (VLAN) is a switched network that is logically segmented on an organizational basis, by functions, project teams, or applications rather than on a physical or geographical basis. For example, all workstations and servers used by a particular workgroup team can be connected to the same VLAN, regardless of their physical connections to the network or the fact that they might be intermingled with other teams. Reconfiguration of the network can be done through software rather than by physically unplugging and moving devices or wires.
A VLAN can be thought of as a broadcast domain that exists within a defined set of switches. A VLAN consists of a number of end systems, either hosts or network equipment (such as bridges and routers), connected by a single bridging domain. The bridging domain is supported on various pieces of network equipment; for example, LAN switches that operate bridging protocols between them with a separate bridge group for each VLAN.
VLANs are created to provide the segmentation services traditionally provided by routers in LAN configurations. VLANs address scalability, security, and network management. Routers in VLAN topologies provide broadcast filtering, security, address summarization, and traffic flow management. None of the switches within the defined group will bridge any frames, not even broadcast frames, between two VLANs. Several key issues described in the following sections need to be considered when designing and building switched LAN internetworks:
• LAN Segmentation, page 8
• Security, page 9
• Broadcast Control, page 9
• VLAN Performance, page 10
• Network Management, page 10
• Network Monitoring Using SNMP, page 10
• Communication Between VLANs
• Relaying Function, page 10
• Native VLAN, page 12
• PVST+, page 13
• Ingress and Egress Rules, page 14
• Integrated Routing and Bridging, page 14
LAN Segmentation
VLANs allow logical network topologies to overlay the physical switched infrastructure such that any arbitrary collection of LAN ports can be combined into an autonomous user group or community of interest. The technology logically segments the network into separate Layer 2 broadcast domains whereby packets are switched between ports designated to be within the same VLAN. By containing traffic originating on a particular LAN only to other LANs in the same VLAN, switched virtual networks
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avoid wasting bandwidth, a drawback inherent to traditional bridged and switched networks in which packets are often forwarded to LANs with no need for them. Implementation of VLANs also improves scalability, particularly in LAN environments that support broadcast- or multicast-intensive protocols and applications that flood packets throughout the network.
Figure 1 illustrates the difference between traditional physical LAN segmentation and logical VLAN segmentation.
Figure 1 LAN Segmentation and VLAN Segmentation
Security
VLANs improve security by isolating groups. High-security users can be grouped into a VLAN, possibly on the same physical segment, and no users outside that VLAN can communicate with them.
Broadcast Control
Just as switches isolate collision domains for attached hosts and only forward appropriate traffic out a particular port, VLANs provide complete isolation between VLANs. A VLAN is a bridging domain, and all broadcast and multicast traffic is contained within it.
CatalystVLAN switch
VLAN 1
VLAN segmentationTraditional LAN segmentation
VLAN 2 VLAN 3
LAN 1
Shared hub
Shared hub
Shared hub
Floor 3
Floor 2
Floor 1
LAN 2
LAN 3
S66
19
CatalystVLAN switch
CatalystVLAN switch
Router
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VLAN Performance
The logical grouping of users allows an accounting group to make intensive use of a networked accounting system assigned to a VLAN that contains just that accounting group and its servers. That group’s work will not affect other users. The VLAN configuration improves general network performance by not slowing down other users sharing the network.
Network Management
The logical grouping of users allows easier network management. It is not necessary to pull cables to move a user from one network to another. Adds, moves, and changes are achieved by configuring a port into the appropriate VLAN.
Network Monitoring Using SNMP
SNMP support has been added to provide mib-2 interfaces sparse table support for Fast Ethernet subinterfaces. Monitor your VLAN subinterface using the show vlans EXEC command. For more information on configuring SNMP on your Cisco network device or enabling an SNMP agent for remote access, refer to the “Configuring SNMP” chapter in the Cisco IOS Configuration Fundamentals Configuration Guide.
Communication Between VLANs
Communication between VLANs is accomplished through routing, and the traditional security and filtering functions of the router can be used. Cisco IOS software provides network services such as security filtering, quality of service (QoS), and accounting on a per-VLAN basis. As switched networks evolve to distributed VLANs, Cisco IOS software provides key inter-VLAN communications and allows the network to scale.
Before Cisco IOS Release 12.2, Cisco IOS support for interfaces that have 802.1Q encapsulation configured is IP, IP multicast, and IPX routing between respective VLANs represented as subinterfaces on a link. New functionality has been added in IEEE 802.1Q support for bridging on those interfaces and the capability to configure and use integrated routing and bridging (IRB).
Relaying Function
The relaying function level, as displayed in Figure 2, is the lowest level in the architectural model described in the IEEE 802.1Q standard and presents three types of rules:
• Ingress rules—Rules relevant to the classification of received frames belonging to a VLAN.
• Forwarding rules between ports—Rules decide whether to filter or forward the frame.
• Egress rules (output of frames from the switch)—Rules decide if the frame must be sent tagged or untagged.
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Figure 2 Relaying Function
The Tagging Scheme
Figure 3 shows the tagging scheme proposed by the 802.3ac standard, that is, the addition of the four octets after the source MAC address. Their presence is indicated by a particular value of the EtherType field (called TPID), which has been fixed to be equal to 0x8100. When a frame has the EtherType equal to 0x8100, this frame carries the tag IEEE 802.1Q/802.1p. The tag is stored in the following two octets and it contains 3 bits of user priority, 1 bit of Canonical Format Identifier (CFI), and 12 bits of VLAN ID (VID). The 3 bits of user priority are used by the 802.1p standard; the CFI is used for compatibility reasons between Ethernet-type networks and Token Ring-type networks. The VID is the identification of the VLAN, which is basically used by the 802.1Q standard; being on 12 bits, it allows the identification of 4096 VLANs.
After the two octets of TPID and the two octets of the Tag Control Information field there are two octets that originally would have been located after the Source Address field where there is the TPID. They contain either the MAC length in the case of IEEE 802.3 or the EtherType in the case of Ethernet version 2.
5471
3
Port stateinformation
Ingressrules
Forwardingprocess
Filteringdatabase
Port stateinformation
Egressrules
Framereception
Frametransmission
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Figure 3 Tagging Scheme
The EtherType and VLAN ID are inserted after the MAC source address, but before the original Ethertype/Length or Logical Link Control (LLC). The 1-bit CFI included a T-R Encapsulation bit so that Token Ring frames can be carried across Ethernet backbones without using 802.1H translation.
Frame Control Sequence Recomputation
Figure 4 shows how adding a tag in a frame recomputes the Frame Control Sequence. 802.1p and 802.1Q share the same tag.
Figure 4 Adding a Tag Recomputes the Frame Control Sequence
Native VLAN
Each physical port has a parameter called PVID. Every 802.1Q port is assigned a PVID value that is of its native VLAN ID (default is VLAN 1). All untagged frames are assigned to the LAN specified in the PVID parameter. When a tagged frame is received by a port, the tag is respected. If the frame is untagged, the value contained in the PVID is considered as a tag. Because the frame is untagged and the PVID is tagged to allow the coexistence, as shown in Figure 5, on the same pieces of cable of VLAN-aware bridge/stations and of VLAN-unaware bridges/stations. Consider, for example, the two stations
5471
2
Destination address
Source address
EtherType = 0x8100
Tag control information
MAC length/type
Data
VID (VLAN ID) - 12 bits
Userpriority CFI
PAD
FCS
6
6
2
2
2
Variable
4
5471
1
Dest FCSSrc Len/Etype Data
Dest
PRI VLAN ID
Token ring encapsulation flag
Taggedframe
Originalframe
(VLAN ID and TR encapsulationsare 802.1Q,not 802.1p)
Src Etype Len/EtypeTag FCSData
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connected to the central trunk link in the lower part of Figure 5. They are VLAN-unaware and they will be associated to the VLAN C, because the PVIDs of the VLAN-aware bridges are equal to VLAN C. Because the VLAN-unaware stations will send only untagged frames, when the VLAN-aware bridge devices receive these untagged frames they will assign them to VLAN C.
Figure 5 Native VLAN
PVST+
PVST+ provides support for 802.1Q trunks and the mapping of multiple spanning trees to the single spanning tree of 802.1Q switches.
The PVST+ architecture distinguishes three types of regions:
• A PVST region
• A PVST+ region
• A MST region
Each region consists of a homogenous type of switch. A PVST region can be connected to a PVST+ region by connecting two ISL ports. Similarly, a PVST+ region can be connected to an MST region by connecting two 802.1Q ports.
At the boundary between a PVST region and a PVST+ region the mapping of spanning trees is one-to-one. At the boundary between a MST region and a PVST+ region, the ST in the MST region maps to one PVST in the PVST+ region. The one it maps to is called the common spanning tree (CST). The default CST is the PVST of VLAN 1 (Native VLAN).
All PVSTs, except for the CST, are tunneled through the MST region. Tunneling means that bridge protocol data units (BPDUs) are flooded through the MST region along the single spanning tree present in the MST region.
PVID = C PVID = C
PVID = C
PVID = C
VLAN-unawareend station
Trunklink
PVID = A
VLAN A
VLAN-awarebridge
VLAN-awarebridge
VLAN B
VLAN A
VLAN B
VLAN C
5471
0
Accessports
Accessports
PVID = B
PVID = A
PVID = B
VLAN-awareend station
VLAN-unawareend station
VLAN-unawareend station
VLAN BVLAN C
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Ingress and Egress Rules
The BPDU transmission on the 802.1Q port of a PVST+ router will be implemented in compliance with the following rules:
• The CST BPDU (of VLAN 1, by default) is sent to the IEEE address.
• All the other BPDUs are sent to Shared Spanning Tree Protocol (SSTP)-Address and encapsulated with Logical Link Control-Subnetwork Access Protocol (LLC-SNAP) header.
• The BPDU of the CST and BPDU of the VLAN equal to the PVID of the 802.1Q trunk are sent untagged.
• All other BPDUs are sent tagged with the VLAN ID.
• The CST BPDU is also sent to the SSTP address.
• Each SSTP-addressed BPDU is also tailed by a Tag-Length-Value for the PVID checking.
The BPDU reception on the 802.1Q port of a PVST+ router will follow these rules:
• All untagged IEEE addressed BPDUs must be received on the PVID of the 802.1Q port.
• The IEEE addressed BPDUs whose VLAN ID matches the Native VLAN are processed by CST.
• All the other IEEE addressed BPDUs whose VLAN ID does not match the Native VLAN and whose port type is not of 802.1Q are processed by the spanning tree of that particular VLAN ID.
• The SSTP addressed BPDU whose VLAN ID is not equal to the TLV are dropped and the ports are blocked for inconsistency.
• All the other SSTP addressed BPDUs whose VLAN ID is not equal to the Native VLAN are processed by the spanning tree of that particular VLAN ID.
• The SSTP addressed BPDUs whose VLAN ID is equal to the Native VLAN are dropped. It is used for consistency checking.
Integrated Routing and Bridging
IRB enables a user to route a given protocol between routed interfaces and bridge groups or route a given protocol between the bridge groups. Integrated routing and bridging is supported on the following protocols:
• IP
• IPX
• AppleTalk
VLAN ColorsVLAN switching is accomplished through frame tagging where traffic originating and contained within a particular virtual topology carries a unique VLAN ID as it traverses a common backbone or trunk link. The VLAN ID enables VLAN switching devices to make intelligent forwarding decisions based on the embedded VLAN ID. Each VLAN is differentiated by a color, or VLAN identifier. The unique VLAN ID determines the frame coloring for the VLAN. Packets originating and contained within a particular VLAN carry the identifier that uniquely defines that VLAN (by the VLAN ID).
The VLAN ID allows VLAN switches and routers to selectively forward packets to ports with the same VLAN ID. The switch that receives the frame from the source station inserts the VLAN ID and the packet is switched onto the shared backbone network. When the frame exits the switched LAN, a switch
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strips the header and forwards the frame to interfaces that match the VLAN color. If you are using a Cisco network management product such as VlanDirector, you can actually color code the VLANs and monitor VLAN graphically.
Implementing VLANSNetwork managers can logically group networks that span all major topologies, including high-speed technologies such as, ATM, FDDI, and Fast Ethernet. By creating virtual LANs, system and network administrators can control traffic patterns and react quickly to relocations and keep up with constant changes in the network due to moving requirements and node relocation just by changing the VLAN member list in the router configuration. They can add, remove, or move devices or make other changes to network configuration using software to make the changes.
Issues regarding creating VLANs should have been addressed when you developed your network design. Issues to consider include the following:
• Scalability
• Performance improvements
• Security
• Network additions, moves, and changes
Communication Between VLANsCisco IOS software provides full-feature routing at Layer 3 and translation at Layer 2 between VLANs. Five different protocols are available for routing between VLANs:
• Inter-Switch Link Protocol, page 15
• IEEE 802.10 Protocol, page 16
• IEEE 802.1Q Protocol, page 16
• ATM LANE Protocol, page 16
• ATM LANE Fast Simple Server Replication Protocol, page 16
All five of these technologies are based on OSI Layer 2 bridge multiplexing mechanisms.
Inter-Switch Link Protocol
The Inter-Switch Link (ISL) protocol is used to interconnect two VLAN-capable Ethernet, Fast Ethernet, or Gigabit Ethernet devices, such as the Catalyst 3000 or 5000 switches and Cisco 7500 routers. The ISL protocol is a packet-tagging protocol that contains a standard Ethernet frame and the VLAN information associated with that frame. The packets on the ISL link contain a standard Ethernet, FDDI, or Token Ring frame and the VLAN information associated with that frame. ISL is currently supported only over Fast Ethernet links, but a single ISL link, or trunk, can carry different protocols from multiple VLANs.
Procedures for configuring ISL and Token Ring ISL (TRISL) features are provided in “Configuring Routing Between VLANs with Inter-Switch Link Encapsulation” section on page 21.
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IEEE 802.10 Protocol
The IEEE 802.10 protocol provides connectivity between VLANs. Originally developed to address the growing need for security within shared LAN/MAN environments, it incorporates authentication and encryption techniques to ensure data confidentiality and integrity throughout the network. Additionally, by functioning at Layer 2, it is well suited to high-throughput, low-latency switching environments. The IEEE 802.10 protocol can run over any LAN or HDLC serial interface.
Procedures for configuring routing between VLANs with IEEE 802.10 encapsulation are provided in the “Configuring Routing Between VLANs with IEEE 802.10 Encapsulation” section on page 37.
IEEE 802.1Q Protocol
The IEEE 802.1Q protocol is used to interconnect multiple switches and routers, and for defining VLAN topologies. Cisco currently supports IEEE 802.1Q for Fast Ethernet and Gigabit Ethernet interfaces.
Note Cisco does not support IEEE 802.1Q encapsulation for Ethernet interfaces.
Procedures for configuring routing between VLANs with IEEE 802.1Q encapsulation are provided in the “Configuring Routing Between VLANs with IEEE 802.1Q Encapsulation” section on page 39.
ATM LANE Protocol
The ATM LAN Emulation (LANE) protocol provides a way for legacy LAN users to take advantage of ATM benefits without requiring modifications to end-station hardware or software. LANE emulates a broadcast environment like IEEE 802.3 Ethernet on top of an ATM network that is a point-to-point environment.
LANE makes ATM function like a LAN. LANE allows standard LAN drivers like NDIS and ODI to be used. The virtual LAN is transparent to applications. Applications can use normal LAN functions without the underlying complexities of the ATM implementation. For example, a station can send broadcasts and multicasts, even though ATM is defined as a point-to-point technology and does not support any-to-any services.
To accomplish this, special low-level software is implemented on an ATM client workstation, called the LAN Emulation Client (LEC). The client software communicates with a central control point called a LAN Emulation Server (LES). A broadcast and unknown server (BUS) acts as a central point to distribute broadcasts and multicasts. The LAN Emulation Configuration Server (LECS) holds a database of LECs and the ELANs they belong to. The database is maintained by a network administrator.
These protocols are described in detail in the Cisco Internetworking Design Guide.
ATM LANE Fast Simple Server Replication Protocol
To improve the ATM LANE Simple Server Replication Protocol (SSRP), Cisco introduced the ATM LANE Fast Simple Server Replication Protocol (FSSRP). FSSRP differs from LANE SSRP in that all configured LANE servers of an ELAN are always active. FSSRP-enabled LANE clients have virtual circuits (VCs) established to a maximum of four LANE servers and BUSs at one time. If a single LANE server goes down, the LANE client quickly switches over to the next LANE server and BUS, resulting in no data or LE ARP table entry loss and no extraneous signalling.
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The FSSRP feature improves upon SSRP such that LANE server and BUS switchover for LANE clients is immediate. With SSRP, a LANE server would go down, and depending on the network load, it may have taken considerable time for the LANE client to come back up joined to the correct LANE server and BUS. In addition to going down with SSRP, the LANE client would do the following:
• Clear out its data direct VCs
• Clear out its LE ARP entries
• Cause substantial signalling activity and data loss
FSSRP was designed to alleviate these problems with the LANE client. With FSSRP, each LANE client is simultaneously joined to up to four LANE servers and BUSs. The concept of the master LANE server and BUS is maintained; the LANE client uses the master LANE server when it needs LANE server BUS services. However, the difference between SSRP and FSSRP is that if and when the master LANE server goes down, the LANE client is already connected to multiple backup LANE servers and BUSs. The LANE client simply uses the next backup LANE server and BUS as the master LANE server and BUS.
VLAN InteroperabilityCisco IOS features bring added benefits to the VLAN technology. Enhancements to ISL, IEEE 802.10, and ATM LANE implementations enable routing of all major protocols between VLANs. These enhancements allow users to create more robust networks incorporating VLAN configurations by providing communications capabilities between VLANs.
Inter-VLAN Communications
The Cisco IOS supports full routing of several protocols over ISL and ATM LANE VLANs. IP, Novell IPX, and AppleTalk routing are supported over IEEE 802.10 VLANs. Standard routing attributes such as network advertisements, secondaries, and help addresses are applicable, and VLAN routing is fast switched. Table 4 shows protocols supported for each VLAN encapsulation format and corresponding Cisco IOS software releases.
Table 4 Inter-VLAN Routing Protocol Support
Protocol ISL ATM LANE IEEE 802.10
IP Release 11.1 Release 10.3 Release 11.1
Novell IPX (default encapsulation)
Release 11.1 Release 10.3 Release 11.1
Novell IPX (configurable encapsulation)
Release 11.3 Release 10.3 Release 11.3
AppleTalk Phase II Release 11.3 Release 10.3 —
DECnet Release 11.3 Release 11.0 —
Banyan VINES Release 11.3 Release 11.2 —
XNS Release 11.3 Release 11.2 —
CLNS Release 12.1 — —
IS-IS Release 12.1 — —
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VLAN Translation
VLAN translation refers to the ability of the Cisco IOS software to translate between different VLANs or between VLAN and non-VLAN encapsulating interfaces at Layer 2. Translation is typically used for selective inter-VLAN switching of nonroutable protocols and to extend a single VLAN topology across hybrid switching environments. It is also possible to bridge VLANs on the main interface; the VLAN encapsulating header is preserved. Topology changes in one VLAN domain do not affect a different VLAN.
Designing Switched VLANsBy the time you are ready to configure routing between VLANs, you will have already defined them through the switches in your network. Issues related to network design and VLAN definition should be addressed during your network design. Refer to the Cisco Internetworking Design Guide and appropriate switch documentation for information on these topics:
• Sharing resources between VLANs
• Load balancing
• Redundant links
• Addressing
• Segmenting networks with VLANs—Segmenting the network into broadcast groups improves network security. Use router access lists based on station addresses, application types, and protocol types.
• Routers and their role in switched networks—In switched networks, routers perform broadcast management, route processing, and distribution, and provide communication between VLANs. Routers provide VLAN access to shared resources and connect to other parts of the network that are either logically segmented with the more traditional subnet approach or require access to remote sites across wide-area links.
How to Configure Routing Between VLANSThis section contains the following configuration procedure groups:
• Configuring a VLAN Range, page 18
• Configuring Routing Between VLANs with Inter-Switch Link Encapsulation
• Configuring Routing Between VLANs with IEEE 802.10 Encapsulation
• Configuring Routing Between VLANs with IEEE 802.1Q Encapsulation
• Configuring IEEE 802.1Q-in-Q VLAN Tag Termination
Configuring a VLAN RangeUsing the VLAN Range feature, you can group VLAN subinterfaces together so that any command entered in a group applies to every subinterface within the group. This capability simplifies configurations and reduces command parsing.
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Restrictions
• Each command you enter while you are in interface configuration mode with the interface range command is executed as it is entered. The commands are not batched together for execution after you exit interface configuration mode. If you exit interface configuration mode while the commands are being executed, some commands might not be executed on some interfaces in the range. Wait until the command prompt reappears before exiting interface configuration mode.
• The no interface range command is not supported. You must delete individual subinterfaces to delete a range.
Supported Platforms
For Cisco IOS Release 12.2(13)T, the following platforms are supported:
• Cisco 6400 series
• Cisco 7200 series
• Cisco 7401 ASR router
Benefits
The VLAN Range feature provides the following benefits:
Simultaneous Configurations
Identical commands can be entered once for a range of subinterfaces, rather than being entered separately for each subinterface.
Overlapping Range Configurations
Overlapping ranges of subinterfaces can be configured.
Customized Subinterfaces
Individual subinterfaces within a range can be customized or deleted.
Configuring a Range of VLAN Subinterfaces
Use the following commands to configure a range of VLAN subinterfaces.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface range {{ethernet | fastethernet | gigabitethernet | atm}
slot/interface.subinterface - {{ethernet | fastethernet | gigabitethernet | atm}slot/interface.subinterface}]
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4. encapsulation dot1Q vlan-id
5. no shutdown
6. exit
7. show running-config
8. show interfaces
DETAILED STEPS
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface range {{ethernet | fastethernet | gigabitethernet | atm} slot/interface.subinterface - {{ethernet | fastethernet | gigabitethernet | atm}slot/interface.subinterface}
Example:Router(config)# interface range fastethernet5/1.1 - fastethernet5/1.4
Selects the range of subinterfaces to be configured.
Note The spaces around the dash are required. For example, the command interface range fastethernet 1 - 5 is valid; the command interface range fastethernet 1-5 is not valid.
Step 4 encapsulation dot1Q vlan-id
Example:Router(config-if)# encapsulation dot1Q 301
Applies a unique VLAN ID to each subinterface within the range.
• vlan-id—Virtual LAN identifier. The allowed range is from 1 to 4095.
• The VLAN ID specified by the vlan-id argument is applied to the first subinterface in the range. Each subsequent interface is assigned a VLAN ID, which is the specified vlan-id plus the subinterface number minus the first subinterface number (VLAN ID + subinterface number – first subinterface number).
Step 5 no shutdown
Example:Router(config-if)# no shutdown
Activates the interface.
• This command is required only if you shut down the interface.
Step 6 exit
Example:Router(config-if)# exit
Returns to privileged EXEC mode.
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Configuring Routing Between VLANs with Inter-Switch Link EncapsulationThis section describes the Inter-Switch Link (ISL) protocol and provides guidelines for configuring ISL and Token Ring ISL (TRISL) features. This section contains the following:
• Frame Tagging in ISL, page 21
• Configuring AppleTalk Routing over ISL, page 22
• Configuring Banyan VINES Routing over ISL, page 24
• Configuring DECnet Routing over ISL, page 25
• Configuring the Hot Standby Router Protocol over ISL, page 26
• Configuring IP Routing over TRISL, page 28
• Configuring IPX Routing on 802.10 VLANs over ISL, page 29
• Configuring IPX Routing over TRISL, page 31
• Configuring VIP Distributed Switching over ISL, page 32
• Configuring XNS Routing over ISL, page 34
• Configuring CLNS Routing over ISL, page 35
• Configuring IS-IS Routing over ISL, page 36
Frame Tagging in ISL
ISL is a Cisco protocol for interconnecting multiple switches and maintaining VLAN information as traffic goes between switches. ISL provides VLAN capabilities while maintaining full wire speed performance on Fast Ethernet links in full- or half-duplex mode. ISL operates in a point-to-point environment and will support up to 1000 VLANs. You can define virtually as many logical networks as are necessary for your environment.
With ISL, an Ethernet frame is encapsulated with a header that transports VLAN IDs between switches and routers. A 26-byte header that contains a 10-bit VLAN ID is propounded to the Ethernet frame.
A VLAN ID is added to the frame only when the frame is prepended for a nonlocal network. Figure 6 shows VLAN packets traversing the shared backbone. Each VLAN packet carries the VLAN ID within the packet header.
Step 7 show running-config
Example:Router# show running-config
Verifies subinterface configuration.
Step 8 show interfaces
Example:Router# show interfaces
Verifies that subinterfaces have been created.
Command Purpose
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Figure 6 VLAN Packets Traversing the Shared Backbone
You can configure routing between any number of VLANs in your network. This section documents the configuration tasks for each protocol supported with ISL encapsulation. The basic process is the same, regardless of the protocol being routed. It involves the following tasks:
• Enabling the protocol on the router
• Enabling the protocol on the interface
• Defining the encapsulation format as ISL or TRISL
• Customizing the protocol according to the requirements for your environment
Configuring AppleTalk Routing over ISL
AppleTalk can be routed over VLAN subinterfaces using the ISL and IEEE 802.10 VLAN encapsulation protocols. The AppleTalk Routing over ISL and IEEE 802.10 Virtual LANs feature provides full-feature Cisco IOS software AppleTalk support on a per-VLAN basis, allowing standard AppleTalk capabilities to be configured on VLANs.
To route AppleTalk over ISL or IEEE 802.10 between VLANs, you need to customize the subinterface to create the environment in which it will be used. Perform the steps in the order in which they appear.
SUMMARY STEPS
1. enable
2. configure terminal
3. appletalk routing [eigrp router-number]
4. interface type slot/port.subinterface-number
5. encapsulation isl vlan-identifier
or
encapsulation sde said
6. appletalk cable-range cable-range [network.node]
7. appletalk zone zone-name
TokenRing Green
Fast Ethernet
Blue Red
Blue
Green
S66
21RedTokenRing
Blue
Green
Red
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DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 appletalk routing [eigrp router-number]
Example:Router(config)# appletalk routing
Enables AppleTalk routing globally on either ISL or 802.10 interfaces.
Step 4 interface type slot/port.subinterface-number
Example:Router(config)# interface Fddi 1/0.100
Specifies the subinterface the VLAN will use.
Step 5 encapsulation isl vlan-identifier
or
encapsulation sde said
Example:Router(config-if)# encapsulation sde 100
Defines the encapsulation format as either ISL (isl) or IEEE 802.10 (sde), and specifies the VLAN identifier or security association identifier, respectively.
Step 6 appletalk cable-range cable-range [network.node]
Example:Router(config-if)# appletalk cable-range 100-100 100.2
Assigns the AppleTalk cable range and zone for the subinterface.
Step 7 appletalk zone zone-name
Example:Router(config-if)# appletalk zone 100
Assigns the AppleTalk zone for the subinterface.
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Configuring Banyan VINES Routing over ISL
Banyan VINES can be routed over VLAN subinterfaces using the ISL encapsulation protocol. The Banyan VINES Routing over ISL Virtual LANs feature provides full-feature Cisco IOS software Banyan VINES support on a per-VLAN basis, allowing standard Banyan VINES capabilities to be configured on VLANs.
To route Banyan VINES over ISL between VLANs, you need to configure ISL encapsulation on the subinterface. Perform the steps in the following task in the order in which they appear:
SUMMARY STEPS
1. enable
2. configure terminal
3. vines routing [address]
4. interface type slot/port.subinterface-number
5. encapsulation isl vlan-identifier
6. vines metric [whole [fraction]]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 vines routing [address]
Example:Router(config)# vines routing
Enables Banyan VINES routing globally.
Step 4 interface type slot/port.subinterface-number
Example:Router(config)# interface fastethernet 1/0.1
Specifies the subinterface on which ISL will be used.
Step 5 encapsulation isl vlan-identifier
Example:Router(config-if)# encapsulation isl 200
Defines the encapsulation format as ISL (isl), and specifies the VLAN identifier.
Step 6 vines metric [whole [fraction]]
Example:Router(config-if)#vines metric 2
Enables VINES routing metric on an interface.
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Configuring DECnet Routing over ISL
DECnet can be routed over VLAN subinterfaces using the ISL VLAN encapsulation protocols. The DECnet Routing over ISL Virtual LANs feature provides full-feature Cisco IOS software DECnet support on a per-VLAN basis, allowing standard DECnet capabilities to be configured on VLANs.
To route DECnet over ISL VLANs, you need to configure ISL encapsulation on the subinterface. Perform the steps described in the following task in the order in which they appear.
SUMMARY STEPS
1. enable
2. configure terminal
3. decnet [network-number] routing [decnet-address]
4. interface type slot/port.subinterface-number
5. encapsulation isl vlan-identifier
6. decnet cost [cost-value]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 Router(config)# decnet [network-number] routing [decnet-address]
Example:Router(config)# decnet routing 2.1
Enables DECnet on the router.
Step 4 interface type slot/port.subinterface-number
Example:Router(config)# interface fastethernet 1/0.1
Specifies the subinterface on which ISL will be used.
Step 5 encapsulation isl vlan-identifier
Example:Router(config-if)# encapsulation isl 200
Defines the encapsulation format as ISL (isl), and specifies the VLAN identifier.
Step 6 decnet cost [cost-value]
Example:Router(config-if)# decnet cost 4
Enables DECnet cost metric on an interface.
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Configuring the Hot Standby Router Protocol over ISL
The Hot Standby Router Protocol (HSRP) provides fault tolerance and enhanced routing performance for IP networks. HSRP allows Cisco IOS routers to monitor each other’s operational status and very quickly assume packet forwarding responsibility in the event the current forwarding device in the HSRP group fails or is taken down for maintenance. The standby mechanism remains transparent to the attached hosts and can be deployed on any LAN type. With multiple Hot Standby groups, routers can simultaneously provide redundant backup and perform loadsharing across different IP subnets.
Figure 7 illustrates HSRP in use with ISL providing routing between several VLANs.
Figure 7 Hot Standby Router Protocol in VLAN Configurations
A separate HSRP group is configured for each VLAN subnet so that Cisco IOS router A can be the primary and forwarding router for VLANs 10 and 20. At the same time, it acts as backup for VLANs 30 and 40. Conversely, Router B acts as the primary and forwarding router for ISL VLANs 30 and 40, as well as the secondary and backup router for distributed VLAN subnets 10 and 20.
Running HSRP over ISL allows users to configure redundancy between multiple routers that are configured as front ends for VLAN IP subnets. By configuring HSRP over ISLs, users can eliminate situations in which a single point of failure causes traffic interruptions. This feature inherently provides some improvement in overall networking resilience by providing load balancing and redundancy capabilities between subnets and VLANs.
To configure HSRP over ISLs between VLANs, you need to create the environment in which it will be used. Perform the tasks described in the following sections in the order in which they appear.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type slot/port.subinterface-number
Cisco IOSrouter
Cisco VLANswitch
Cisco VLANswitch
ISL ISL
ISL
HSRP
VLAN 20 VLAN 10 VLAN 40
VLAN 10 VLAN 30 VLAN 20
Cisco IOSrouter
S66
20
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4. encapsulation isl vlan-identifier
5. ip address ip-address mask [secondary]
6. standby [group-number] ip [ip-address [secondary]]
7. standby [group-number] timers hellotime holdtime
8. standby [group-number] priority priority
9. standby [group-number] preempt
10. standby [group-number] track type-number [interface-priority]
11. standby [group-number] authentication string
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 Router(config)# interface type slot/port.subinterface-number
Example:Router(config)# interface FastEthernet 1/1.110
Specifies the subinterface on which ISL will be used.
Step 4 encapsulation isl vlan-identifier
Example:Router(config-if)# encapsulation isl 110
Defines the encapsulation format, and specifies the VLAN identifier.
Step 5 ip address ip-address mask [secondary]
Example:Router(config-if)# ip address 10.1.1.2 255.255.255.0
Specifies the IP address for the subnet on which ISL will be used.
Step 6 Router(config-if)# standby [group-number] ip [ip-address [secondary]]
Example:Router(config-if)# standby 1 ip 10.1.1.101
Enables HSRP.
Step 7 Router(config-if)# standby [group-number] timers hellotime holdtime
Example:Router(config-if)# standby 1 timers 10 10
Configures the time between hello packets and the hold time before other routers declare the active router to be down.
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Note For more information on HSRP, see the “Configuring IP Services” chapter in the Cisco IOS IP Configuration Guide.
Configuring IP Routing over TRISL
The IP routing over TRISL VLANs feature extends IP routing capabilities to include support for routing IP frame types in VLAN configurations.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip routing
4. interface type slot/port.subinterface-number
5. encapsulation tr-isl trbrf-vlan vlanid bridge-num bridge-number
6. ip address ip-address mask
Step 8 Router(config-if)# standby [group-number] priority priority
Example:Router(config-if)# standby 1 priority 105
Sets the Hot Standby priority used to choose the active router.
Step 9 Router(config-if)# standby [group-number] preempt
Example:Router(config-if)# standby 1 priority 105
Specifies that if the local router has priority over the current active router, the local router should attempt to take its place as the active router.
Step 10 Router(config-if)# standby [group-number] track type-number [interface-priority]
Example:Router(config-if)# standby 1 track 4 5
Configures the interface to track other interfaces, so that if one of the other interfaces goes down, the Hot Standby priority for the device is lowered.
Step 11 Router(config-if)# standby [group-number] authentication string
Example:Router(config-if)# standby 1 authentication hsrpword7
Selects an authentication string to be carried in all HSRP messages.
Command or Action Purpose
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DETAILED STEPS
Configuring IPX Routing on 802.10 VLANs over ISL
The IPX Encapsulation for 802.10 VLAN feature provides configurable IPX (Novell-FDDI, SAP, SNAP) encapsulation over 802.10 VLAN on router FDDI interfaces to connect the Catalyst 5000 VLAN switch. This feature extends Novell NetWare routing capabilities to include support for routing all standard IPX encapsulations for Ethernet frame types in VLAN configurations. Users with Novell NetWare environments can now configure any one of the three IPX Ethernet encapsulations to be routed using Secure Data Exchange (SDE) encapsulation across VLAN boundaries. IPX encapsulation options now supported for VLAN traffic include the following:
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip routing
Example:Router(config)# ip routing
Enables IP routing on the router.
Step 4 interface type slot/port.subinterface-number
Example:Router(config# interface FastEthernet4/0.1
Specifies the subinterface on which TRISL will be used.
Step 5 encapsulation tr-isl trbrf-vlan vlanid bridge-num bridge-number
Example:Router(config-if# encapsulation tr-isl trbrf-vlan 999 bridge-num 14
Defines the encapsulation for TRISL.
• The DRiP database is automatically enabled when TRISL encapsulation is configured, and at least one TrBRF is defined, and the interface is configured for SRB or for routing with RIF
Step 6 ip address ip-address mask
Example:Router(config-if# ip address 10.5.5.1 255.255.255.0
Sets a primary IP address for an interface.
• A mask identifies the bits that denote the network number in an IP address. When you use the mask to subnet a network, the mask is then referred to as a subnet mask.
Note TRISL encapsulation must be specified for a subinterface before an IP address can be assigned to that subinterface.
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• Novell-FDDI (IPX FDDI RAW to 802.10 on FDDI)
• SAP (IEEE 802.2 SAP to 802.10 on FDDI)
• SNAP (IEEE 802.2 SNAP to 802.10 on FDDI)
NetWare users can now configure consolidated VLAN routing over a single VLAN trunking FDDI interface. Not all IPX encapsulations are currently supported for SDE VLAN. The IPX interior encapsulation support can be achieved by messaging the IPX header before encapsulating in the SDE format. Fast switching will also support all IPX interior encapsulations on non-MCI platforms (for example non-AGS+ and non-7000). With configurable Ethernet encapsulation protocols, users have the flexibility of using VLANs regardless of their NetWare Ethernet encapsulation. Configuring Novell IPX encapsulations on a per-VLAN basis facilitates migration between versions of Netware. NetWare traffic can now be routed across VLAN boundaries with standard encapsulation options (arpa, sap, and snap) previously unavailable. Encapsulation types and corresponding framing types are described in the “Configuring Novell IPX” chapter of the Cisco IOS AppleTalk and Novell IPX Configuration Guide.
Note Only one type of IPX encapsulation can be configured per VLAN (subinterface). The IPX encapsulation used must be the same within any particular subnet; a single encapsulation must be used by all NetWare systems that belong to the same VLAN.
To configure Cisco IOS software on a router with connected VLANs to exchange different IPX framing protocols, perform the steps described in the following task in the order in which they are appear.
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx routing [node]
4. interface fddi slot/port.subinterface-number
5. encapsulation sde vlan-identifier
6. ipx network network encapsulation encapsulation-type
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ipx routing [node]
Example:Router(config)# ipx routing
Enables IPX routing globally.
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Configuring IPX Routing over TRISL
The IPX Routing over ISL VLANs feature extends Novell NetWare routing capabilities to include support for routing all standard IPX encapsulations for Ethernet frame types in VLAN configurations. Users with Novell NetWare environments can configure either SAP or SNAP encapsulations to be routed using the TRISL encapsulation across VLAN boundaries. The SAP (Novell Ethernet_802.2) IPX encapsulation is supported for VLAN traffic.
NetWare users can now configure consolidated VLAN routing over a single VLAN trunking interface. With configurable Ethernet encapsulation protocols, users have the flexibility of using VLANs regardless of their NetWare Ethernet encapsulation. Configuring Novell IPX encapsulations on a per-VLAN basis facilitates migration between versions of Netware. NetWare traffic can now be routed across VLAN boundaries with standard encapsulation options (sap and snap) previously unavailable. Encapsulation types and corresponding framing types are described in the “Configuring Novell IPX” chapter of the Cisco IOS AppleTalk and Novell IPX Configuration Guide.
Note Only one type of IPX encapsulation can be configured per VLAN (subinterface). The IPX encapsulation used must be the same within any particular subnet: A single encapsulation must be used by all NetWare systems that belong to the same LANs.
To configure Cisco IOS software to exchange different IPX framing protocols on a router with connected VLANs, perform the steps in the following task in the order in which they are appear.
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx routing [node]
4. interface type slot/port.subinterface-number
5. encapsulation tr-isl trbrf-vlan trbrf-vlan bridge-num bridge-num
6. ipx network network encapsulation encapsulation-type
Step 4 interface fddi slot/port.subinterface-number
Example:Router(config)# interface 2/0.1
Specifies the subinterface on which SDE will be used.
Step 5 encapsulation sde vlan-identifier
Example:Router(config-if)# encapsulation isl 20
Defines the encapsulation format and specifies the VLAN identifier.
Step 6 ipx network network encapsulation encapsulation-type
Example:Router(config-if)# ipx network 20 encapsulation sap
Specifies the IPX encapsulation among Novell-FDDI, SAP, or SNAP.
Command or Action Purpose
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DETAILED STEPS
Note The default IPX encapsulation format for Cisco IOS routers is “novell-ether” (Novell Ethernet_802.3). If you are running Novell Netware 3.12 or 4.0, the new Novell default encapsulation format is Novell Ethernet_802.2 and you should configure the Cisco router with the IPX encapsulation format “sap.”
Configuring VIP Distributed Switching over ISL
With the introduction of the VIP distributed ISL feature, ISL encapsulated IP packets can be switched on Versatile Interface Processor (VIP) controllers installed on Cisco 7500 series routers.
The second generation VIP2 provides distributed switching of IP encapsulated in ISL in VLAN configurations. Where an aggregation route performs inter-VLAN routing for multiple VLANs, traffic can be switched autonomously on-card or between cards rather than through the central Route Switch Processor (RSP). Figure 8 shows the VIP distributed architecture of the Cisco 7500 series router.
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ipx routing [node]
Example:Router(config)# source-bridge ring-group 100
Enables IPX routing globally.
Step 4 interface type slot/port.subinterface-number
Example:Router(config-if)# interface TokenRing 3/1
Specifies the subinterface on which TRISL will be used.
Step 5 encapsulation tr-isl trbrf-vlan trbrf-vlan bridge-num bridge-num
Example:Router(config-if)#encapsulation tr-isl trbrf-vlan 999 bridge-num 14
Defines the encapsulation for TRISL.
Step 6 ipx network network encapsulation encapsulation-type
Example:Router(config-if)# ipx network 100 encapsulation sap
Specifies the IPX encapsulation on the subinterface by specifying the NetWare network number (if necessary) and the encapsulation type.
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Figure 8 Cisco 7500 Distributed Architecture
This distributed architecture allows incremental capacity increases by installation of additional VIP cards. Using VIP cards for switching the majority of IP VLAN traffic in multiprotocol environments substantially increases routing performance for the other protocols because the RSP offloads IP and can then be dedicated to switching the non-IP protocols.
VIP distributed switching offloads switching of ISL VLAN IP traffic to the VIP card, removing involvement from the main CPU. Offloading ISL traffic to the VIP card substantially improves networking performance. Because you can install multiple VIP cards in a router, VLAN routing capacity is increased linearly according to the number of VIP cards installed in the router.
To configure distributed switching on the VIP, you must first configure the router for IP routing. Perform the tasks described in the following task in the order in which they appear.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip routing
4. interface type slot/port-adapter/port
5. ip route-cache distributed
6. encapsulation isl vlan-identifier
FastEthernet
VLAN1,2,3
VLAN4,5,6
VLAN7,8,9
VLAN10,11,12
VLAN13,14,15
VLAN16,17,18
FastEthernet
VersatileInterface
Processor
Distributed IPforwarding
cache
FastEthernet
FastEthernet
VersatileInterface
Processor
Distributed IPforwarding
cache
FastEthernet
FastEthernet
VersatileInterface
Processor
Distributed IPforwarding
cache
IP routingtable
IP forwardingtable
S66
22
Route Switch Processor
CyBus
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DETAILED STEPS
Configuring XNS Routing over ISL
XNS can be routed over VLAN subinterfaces using the ISL VLAN encapsulation protocol. The XNS Routing over ISL Virtual LANs feature provides full-feature Cisco IOS software XNS support on a per-VLAN basis, allowing standard XNS capabilities to be configured on VLANs.
To route XNS over ISL VLANs, you need to configure ISL encapsulation on the subinterface. Perform the steps described in the following task in the order in which they appear.
SUMMARY STEPS
1. enable
2. configure terminal
3. xns routing [address]
4. interface type slot/port.subinterface-number
5. encapsulation isl vlan-identifier
6. xns network [number]
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip routing
Example:Router(config)# ip routing
Enables IP routing on the router.
• Refer to the IP configuration chapters in the Cisco IOS IP Routing Configuration Guide for guidelines on configuring IP.
Step 4 interface type slot/port-adapter/port
Example:Router(config)# interface FastEthernet1/0/0
Specifies the interface and interface configuration mode.
Step 5 ip route-cache distributed
Example:Router(config-if)# ip route-cache distributed
Enables VIP distributed switching of IP packets on the interface.
Step 6 encapsulation isl vlan-identifier
Example:Router(config-if)# encapsulation isl 1
Defines the encapsulation format as ISL, and specifies the VLAN identifier.
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DETAILED STEPS
Configuring CLNS Routing over ISL
CLNS can be routed over VLAN subinterfaces using the ISL VLAN encapsulation protocol. The CLNS Routing over ISL Virtual LANs feature provides full-feature Cisco IOS software CLNS support on a per-VLAN basis, allowing standard CLNS capabilities to be configured on VLANs.
To route CLNS over ISL VLANs, you need to configure ISL encapsulation on the subinterface. Perform the steps described in the following task in the order in which they appear.
SUMMARY STEPS
1. enable
2. configure terminal
3. clns routing
4. interface type slot/port.subinterface-number
5. encapsulation isl vlan-identifier
6. clns enable
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 xns routing [address]
Example:Router(config)# xns routing 0123.4567.adcb
Enables XNS routing globally.
Step 4 interface type slot/port.subinterface-number
Example:Router(config)# interface fastethernet 1/0.1
Specifies the subinterface on which ISL will be used.
Step 5 encapsulation isl vlan-identifier
Example:Router(config-if)# encapsulation isl 100
Defines the encapsulation format as ISL (isl), and specifies the VLAN identifier.
Step 6 xns network [number]
Example:Router(config-if)# xns network 20
Enables XNS routing on the subinterface.
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DETAILED STEPS
Configuring IS-IS Routing over ISL
IS-IS routing can be enabled over VLAN subinterfaces using the ISL VLAN encapsulation protocol. The IS-IS Routing over ISL Virtual LANs feature provides full-feature Cisco IOS software IS-IS support on a per-VLAN basis, allowing standard IS-IS capabilities to be configured on VLANs.
To enable IS-IS over ISL VLANs, you need to configure ISL encapsulation on the subinterface. Perform the steps described in the following task in the order in which they appear.
SUMMARY STEPS
1. enable
2. configure terminal
3. router isis [tag]
4. net network-entity-title
5. interface type slot/port.subinterface-number
6. encapsulation isl vlan-identifier
7. clns router isis network [tag]
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 clns routing
Example:Router(config)# clns routing
Enables CLNS routing globally.
Step 4 interface type slot/port.subinterface-number
Example:Router(config-if)# interface fastethernet 1/0.1
Specifies the subinterface on which ISL will be used.
Step 5 encapsulation isl vlan-identifier
Example:Router(config-if)# encapsulation isl 100
Defines the encapsulation format as ISL (isl), and specifies the VLAN identifier.
Step 6 clns enable
Example:Router(config-if)# clns enable
Enables CLNS routing on the subinterface.
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DETAILED STEPS
Configuring Routing Between VLANs with IEEE 802.10 EncapsulationThis section describes the required and optional tasks for configuring routing between VLANs with IEEE 802.10 encapsulation.
HDLC serial links can be used as VLAN trunks in IEEE 802.10 VLANs to extend a virtual topology beyond a LAN backbone.
AppleTalk can be routed over VLAN subinterfaces using the ISL or IEEE 802.10 VLANs feature that provides full-feature Cisco IOS software AppleTalk support on a per-VLAN basis, allowing standard AppleTalk capabilities to be configured on VLANs.
AppleTalk users can now configure consolidated VLAN routing over a single VLAN trunking interface. Prior to introduction of this feature, AppleTalk could be routed only on the main interface on a LAN port. If AppleTalk routing was disabled on the main interface or if the main interface was shut down, the
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 router isis [tag]
Example:Router(config)# isis routing test-proc2
Enables IS-IS routing, and enters router configuration mode.
Step 4 net network-entity-title
Example:Router(config)# net 49.0001.0002.aaaa.aaaa.aaaa.00
Configures the NET for the routing process.
Step 5 interface type slot/port.subinterface-number
Example:Router(config-if)# interface fastethernet 2.
Specifies the subinterface on which ISL will be used.
Step 6 encapsulation isl vlan-identifier
Example:Router(config-if)# encapsulation isl 101
Defines the encapsulation format as ISL (isl), and specifies the VLAN identifier.
Step 7 clns router isis network [tag]
Example:Router(config-if)# clns router is-is network test-proc2
Specifies the interfaces that should be actively routing IS-IS.
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entire physical interface would stop routing any AppleTalk packets. With this feature enabled, AppleTalk routing on subinterfaces will be unaffected by changes in the main interface with the main interface in the “no-shut” state.
To route AppleTalk over IEEE 802.10 between VLANs, create the environment in which it will be used by customizing the subinterface and perform the tasks described in the following steps in the order in which they appear.
SUMMARY STEPS
1. enable
2. configure terminal
3. appletalk routing [eigrp router-number]
4. interface fastethernet slot/port.subinterface-number
5. appletalk cable-range cable-range [network.node]
6. appletalk zone zone-name
7. encapsulation sde said
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 appletalk routing [eigrp router-number]
Example:Router(config)# appletalk routing
Enables AppleTalk routing globally.
Step 4 interface fastethernet slot/port.subinterface-number
Example:Router(config)# interface fastethernet 4/1.00
Specifies the subinterface the VLAN will use.
Step 5 appletalk cable-range cable-range [network.node]
Example:Router(config-if)# appletalk 100-100 100.1
Assigns the AppleTalk cable range and zone for the subinterface.
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Note For more information on configuring AppleTalk, see the “Configuring AppleTalk” chapter in the Cisco IOS AppleTalk and Novell IPX Configuration Guide.
Configuring Routing Between VLANs with IEEE 802.1Q EncapsulationThis section describes the required and optional tasks for configuring routing between VLANs with IEEE 802.1Q encapsulation. The IEEE 802.1Q protocol is used to interconnect multiple switches and routers, and for defining VLAN topologies.
Prerequisites
Configuring routing between VLANs with IEEE 802.1Q encapsulation assumes the presence of a single spanning tree and of an explicit tagging scheme with one-level tagging.
You can configure routing between any number of VLANs in your network.
Restrictions
The IEEE 802.1Q standard is extremely restrictive to untagged frames. The standard provides only a per-port VLANs solution for untagged frames. For example, assigning untagged frames to VLANs takes into consideration only the port from which they have been received. Each port has a parameter called a permanent virtual identification (Native VLAN) that specifies the VLAN assigned to receive untagged frames.
The main characteristics of the IEEE 802.1Q are that it assigns frames to VLANs by filtering and that the standard assumes the presence of a single spanning tree and of an explicit tagging scheme with one-level tagging.
This section contains the configuration tasks for each protocol supported with IEEE 802.1Q encapsulation. The basic process is the same, regardless of the protocol being routed. It involves the following tasks:
• Enabling the protocol on the router
• Enabling the protocol on the interface
• Defining the encapsulation format as IEEE 802.1Q
• Customizing the protocol according to the requirements for your environment
Step 6 appletalk zone zone-name
Example:Router(config-if)# appletalk zone eng
Assigns the AppleTalk zone for the subinterface.
Step 7 encapsulation sde said
Example:Router(config-if)# encapsulation sde 100
Defines the encapsulation format as IEEE 802.10 (sde) and specifies the VLAN identifier or security association identifier, respectively.
Command or Action Purpose
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To configure IEEE 802.1Q on your network, perform the following tasks. One of the following tasks is required depending on the protocol being used.
• Configuring AppleTalk Routing over IEEE 802.1Q (required)
• Configuring IP Routing over IEEE 802.1Q (required)
• Configuring IPX Routing over IEEE 802.1Q (required)
The following tasks are optional. Perform the following tasks to connect a network of hosts over a simple bridging-access device to a remote access concentrator bridge between IEEE 802.1Q VLANs. The following sections contain configuration tasks for the Integrated Routing and Bridging, Transparent Bridging, and PVST+ Between VLANs with IEEE 802.1Q Encapsulation:
• Configuring a VLAN for a Bridge Group with Default VLAN1 (optional)
• Configuring a VLAN for a Bridge Group as a Native VLAN (optional)
Configuring AppleTalk Routing over IEEE 802.1Q
AppleTalk can be routed over virtual LAN (VLAN) subinterfaces using the IEEE 802.1Q VLAN encapsulation protocol. AppleTalk Routing provides full-feature Cisco IOS software AppleTalk support on a per-VLAN basis, allowing standard AppleTalk capabilities to be configured on VLANs.
To route AppleTalk over IEEE 802.1Q between VLANs, you need to customize the subinterface to create the environment in which it will be used. Perform the steps in the order in which they appear.
Use the following task to enable AppleTalk routing on IEEE 802.1Q interfaces.
SUMMARY STEPS
1. enable
2. configure terminal
3. appletalk routing [eigrp router-number]
4. interface fastethernet slot/port.subinterface-number
5. encapsulation dot1q vlan-identifier
6. appletalk cable-range cable-range [network.node]
7. appletalk zone zone-name
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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Note For more information on configuring AppleTalk, see the “Configuring AppleTalk” chapter in the Cisco IOS AppleTalk and Novell IPX Configuration Guide.
Configuring IP Routing over IEEE 802.1Q
IP routing over IEEE 802.1Q extends IP routing capabilities to include support for routing IP frame types in VLAN configurations using the IEEE 802.1Q encapsulation.
To route IP over IEEE 802.1Q between VLANs, you need to customize the subinterface to create the environment in which it will be used. Perform the tasks described in the following sections in the order in which they appear.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip routing
4. interface fastethernet slot/port.subinterface-number
5. encapsulation dotlq vlanid
6. ip address ip-address mask
Step 3 appletalk routing [eigrp router-number]
Example:Router(config)# appletalk routing
Enables AppleTalk routing globally.
Step 4 interface fastethernet slot/port.subinterface-number
Example:Router(config)# interface fastethernet 4/1.00
Specifies the subinterface the VLAN will use.
Step 5 encapsulation dot1q vlan-identifier
Example:Router(config-if)# encapsulation dot1q 100
Defines the encapsulation format as IEEE 802.1Q (dot1q), and specifies the VLAN identifier.
Step 6 appletalk cable-range cable-range [network.node]
Example:Router(config-if)# appletalk cable-range 100-100 100.1
Assigns the AppleTalk cable range and zone for the subinterface.
Step 7 appletalk zone zone-name
Example:Router(config-if)# appletalk zone eng
Assigns the AppleTalk zone for the subinterface.
Command or Action Purpose
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DETAILED STEPS
Once you have IP routing enabled on the router, you can customize the characteristics to suit your environment. If necessary, refer to the IP configuration chapters in the Cisco IOS IP Routing Configuration Guide for guidelines on configuring IP.
Configuring IPX Routing over IEEE 802.1Q
IPX routing over IEEE 802.1Q VLANs extends Novell NetWare routing capabilities to include support for routing Novell Ethernet_802.3 encapsulation frame types in VLAN configurations. Users with Novell NetWare environments can configure Novell Ethernet_802.3 encapsulation frames to be routed using IEEE 802.1Q encapsulation across VLAN boundaries.
To configure Cisco IOS software on a router with connected VLANs to exchange IPX Novell Ethernet_802.3 encapsulated frames, perform the steps described in the following task in the order in which they appear.
SUMMARY STEPS
1. enable
2. configure terminal
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip routing
Example:Router(config)# ip routing
Enables IP routing on the router.
Step 4 interface fastethernet slot/port.subinterface-number
Example:Router(config)# interface fastethernet 4/1.101
Specifies the subinterface on which IEEE 802.1Q will be used.
Step 5 encapsulation dot1q vlanid
Example:Router(config-if)# encapsulation dot1q 101
Defines the encapsulation format at IEEE.802.1Q (dot1q) and specifies the VLAN identifier.
Step 6 ip address ip-address mask
Example:Router(config-if)# ip addr 10.0.0.11 255.0.0.0
Sets a primary IP address and mask for the interface.
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3. ipx routing [node]
4. interface fastethernet slot/port.subinterface-number
5. encapsulation dotlq vlanid
6. ipx network network
DETAILED STEPS
Configuring a VLAN for a Bridge Group with Default VLAN1
Use the following task to configure a VLAN associated with a bridge group with a default native VLAN.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface fastethernet slot/port.subinterface-number
4. encapsulation dotlq vlanid
5. bridge-group bridge-group
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ipx routing [node]
Example:Router(config)# ipx routing
Enables IPX routing globally.
Step 4 interface fastethernet slot/port.subinterface-number
Example:Router(config)# interface fastethernet 4/1.102
Specifies the subinterface on which IEEE 802.1Q will be used.
Step 5 encapsulation dot1q vlanid
Example:Router(config-if)# encapsulation dot1q 102
Defines the encapsulation format at IEEE.802.1Q (dot1q) and specifies the VLAN identifier.
Step 6 ipx network network
Example:Router(config-if)# ipx network 100
Specifies the IPX network number.
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DETAILED STEPS
Configuring a VLAN for a Bridge Group as a Native VLAN
Use the following task to configure a VLAN associated to a bridge group as a native VLAN.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface fastethernet slot/port
4. encapsulation dotlq vlanid native
5. bridge-group bridge-group
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface fastethernet slot/port.subinterface-number
Example:Router(config)# interface fastethernet 4/1.100
Selects a particular interface to configure.
Step 4 encapsulation dot1q vlanid
Example:Router(config-subif)# encapsulation dot1q 1
Defines the encapsulation format at IEEE.802.1Q (dot1q) and specifies the VLAN identifier.
• The specified VLAN is by default the native VLAN.
Note If there is no explicitly defined native VLAN, the default VLAN1 becomes the native VLAN.
Step 5 bridge-group bridge-group
Example:Router(config-subif)# bridge-group 1
Assigns the bridge group to the interface.
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DETAILED STEPS
Note If there is an explicitly defined native VLAN, VLAN1 will only be used to process CST.
Configuring IEEE 802.1Q-in-Q VLAN Tag TerminationEncapsulating IEEE 802.1Q VLAN tags within 802.1Q enables service providers to use a single VLAN to support customers who have multiple VLANs. The IEEE 802.1Q-in-Q VLAN Tag Termination feature on the subinterface level preserves VLAN IDs and keeps traffic in different customer VLANs segregated.
Prerequisites
You must have checked Feature Navigator to verify that your Cisco device and software image support this feature.
You must be connected to an Ethernet device that supports double VLAN tag imposition/disposition or switching.
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface fastethernet slot/port.subinterface-number
Example:Router(config)# interface fastethernet 4/1.100
Selects a particular interface to configure.
Step 4 encapsulation dot1q vlanid native
Example:Router(config-subif)# encapsulation dot1q 20 native
Defines the encapsulation format at IEEE.802.1Q (dot1q) and specifies the VLAN identifier. VLAN 20 is specified as the native VLAN.
Note If there is no explicitly defined native VLAN, the default VLAN1 becomes the native VLAN.
Step 5 bridge-group bridge-group
Example:Router(config-subif)# bridge-group 1
Assigns the bridge group to the interface.
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Restrictions
The following restrictions apply to the Cisco 10000 series Internet router:
• Supported on Ethernet, FastEthernet, or Gigabit Ethernet interfaces.
• Supports only Point-to-Point Protocol over Ethernet (PPPoE) packets that are double-tagged for Q-in-Q VLAN tag termination.
• IP and Multiprotocol Label Switching (MPLS) packets are not supported.
• Modular QoS can be applied to unambiguous subinterfaces only.
• Limited ACL support.
IEEE 802.1Q-in-Q VLAN Tag Termination on Subinterfaces
IEEE 802.1Q-in-Q VLAN Tag Termination simply adds another layer of IEEE 802.1Q tag (called “metro tag” or “PE-VLAN”) to the 802.1Q tagged packets that enter the network. The purpose is to expand the VLAN space by tagging the tagged packets, thus producing a “double-tagged” frame. The expanded VLAN space allows the service provider to provide certain services, such as Internet access on specific VLANs for specific customers, and yet still allows the service provider to provide other types of services for their other customers on other VLANs.
Generally the service provider’s customers require a range of VLANs to handle multiple applications. Service providers can allow their customers to use this feature to safely assign their own VLAN IDs on subinterfaces because these subinterface VLAN IDs are encapsulated within a service-provider designated VLAN ID for that customer. Therefore there is no overlap of VLAN IDs among customers, nor does traffic from different customers become mixed. The double-tagged frame is “terminated” or assigned on a subinterface with an expanded encapsulation dot1q command that specifies the two VLAN ID tags (outer VLAN ID and inner VLAN ID) terminated on the subinterface. See Figure 9 on page 47.
IEEE 802.1Q-in-Q VLAN Tag Termination is generally supported on whichever Cisco IOS features or protocols are supported on the subinterface; the exception is that Cisco 10000 series Internet router only supports PPPoE. For example if you can run PPPoE on the subinterface, you can configure a double-tagged frame for PPPoE. The only restriction is whether you assign ambiguous or unambiguous subinterfaces for the inner VLAN ID. See the “Unambiguous and Ambiguous Subinterfaces” section on page 49.
Note The Cisco 10000 series Internet router only supports PPPoE over Q-in-Q (PPPoEQinQ).
The primary benefit for the service provider is reduced number of VLANs supported for the same number of customers. Other benefits of this feature include:
• PPPoE scalability. By expanding the available VLAN space from 4096 to approximately 16.8 million (4096 times 4096), the number of PPPoE sessions that can be terminated on a given interface is multiplied.
• When deploying Gigabyte Ethernet DSL Access Multiplexer (DSLAM) in wholesale model, you can assign the inner VLAN ID to represent the end-customer virtual circuit (VC) and assign the outer VLAN ID to represent the service provider ID.
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The Q-in-Q VLAN tag termination feature is simpler than the IEEE 802.1Q tunneling feature deployed for the Catalyst 6500 series switches or the Catalyst 3550 and Catalyst 3750 switches. Whereas switches require IEEE 802.1Q tunnels on interfaces to carry double-tagged traffic, routers need only encapsulate Q-in-Q VLAN tags within another level of 802.1Q tags in order for the packets to arrive at the correct destination as shown in Figure 9.
Figure 9Untagged, 802.1Q-Tagged, and Double-Tagged Ethernet Frames
Cisco 10000 Series Internet Router Application
For the emerging broadband Ethernet-based DSLAM market, the Cisco 10000 series Internet router supports Q-in-Q encapsulation. With the Ethernet-based DSLAM model shown in Figure 10, customers typically get their own VLAN and all these VLANs are aggregated on a DSLAM.
Double-tagged frame
802.1Q frame fromcustomer network
Original Ethernet frame
Destinationaddress
Length/EtherType
Frame CheckSequence
Sourceaddress
SADA Len/Etype Data FCS
SADA Len/Etype DataEtype Tag FCS
SADA Len/Etype DataEtype Tag Etype Tag FCS
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Figure 10 Broadband Ethernet-based DSLAM Model of Q-in-Q VLANs
VLAN aggregation on a DSLAM will result in a lot of aggregate VLANs that at some point need to be terminated on the broadband remote access servers (BRAS). Although the model could connect the DSLAMs directly to the BRAS, a more common model uses the existing Ethernet-switched network where each DSLAM VLAN ID is tagged with a second tag (Q-in-Q) as it connects into the Ethernet-switched network.
The only model that is supported is PPPoE over Q-in-Q (PPPoEoQinQ). This can either be a PPP terminated session or as a L2TP LAC session. No IP over Q-in-Q is supported.
The Cisco 10000 series Internet router already supports plain PPPoE and PPP over 802.1Q encapsulation. Supporting PPP over Q-in-Q encapsulation is new. PPP over Q-in-Q encapsulation processing is an extension to 802.1q encapsulation processing. A Q-in-Q frame looks like a VLAN 802.1Q frame, only it has two 802.1Q tags instead of one. See Figure 9.
PPP over Q-in-Q encapsulation supports configurable outer tag Ethertype. The configurable Ethertype field values are 0x8100 (default), 0x9100, and 0x9200. See Figure 11.
Figure 11 Supported Configurable Ethertype Field Values
Security ACL Application on the Cisco 10000 Series Internet Router
The IEEE 802.1Q-in-Q VLAN Tag Termination feature provides limited security access control list (ACL) support for the Cisco 10000 series Internet router.
If you apply an ACL to PPPoE traffic on a Q-in-Q subinterface in a VLAN, apply the ACL directly on the PPPoE session, using virtual access interfaces (VAIs) or RADIUS attribute 11 or 242.
You can apply ACLs to virtual access interfaces by configuring them under virtual template interfaces. You can also configure ACLs by using RADIUS attribute 11 or 242. When you use attribute 242, a maximum of 30,000 sessions can have ACLs.
ACLs that are applied to the VLAN Q-in-Q subinterface have no effect and are silently ignored. In the following example, ACL 1 that is applied to the VLAN Q-in-Q subinterface level will be ignored:
GigE
BRAS
QinQL2/L3 switch
L2/L3 switch
DSLAM
DSLAM
FE/GE
Outer VLAN1
VLAN1
VLAN10
VLAN20
VLAN30
1701
36
L2/L3 switchOuter VLAN
2
L2/L3 switchOuter VLAN
2
Outer VLAN3
DA SA0x81000x91000x9200
Tag 0x8100 Tag Len/Etype Data FCS
1701
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Router(config)# interface FastEthernet3/0/0.100Router(config-subif)# encapsulation dot1q 100 second-dot1q 200Router(config-subif)# ip access-group 1
Unambiguous and Ambiguous Subinterfaces
The encapsulation dot1q command is used to configure Q-in-Q termination on a subinterface. The command accepts an Outer VLAN ID and one or more Inner VLAN IDs. The outer VLAN ID always has a specific value, while inner VLAN ID can either be a specific value or a range of values.
A subinterface that is configured with a single Inner VLAN ID is called an unambiguous Q-in-Q subinterface. In the following example, Q-in-Q traffic with an Outer VLAN ID of 101 and an Inner VLAN ID of 1001 is mapped to the Gigabit Ethernet 1/0.100 subinterface:
Router(config)# interface gigabitEehernet1/0.100Router(config-subif)# encapsulation dot1q 101 second-dot1q 1001
A subinterface that is configured with multiple Inner VLAN IDs is called an ambiguous Q-in-Q subinterface. By allowing multiple Inner VLAN IDs to be grouped together, ambiguous Q-in-Q subinterfaces allow for a smaller configuration, improved memory usage and better scalability.
In the following example, Q-in-Q traffic with an Outer VLAN ID of 101 and Inner VLAN IDs anywhere in the 2001-2100 and 3001-3100 range is mapped to the Gigabit Ethernet 1/0.101 subinterface.:
Router(config)# interface gigabitethernet1/0.101Router(config-subif)# encapsulation dot1q 101 second-dot1q 2001-2100,3001-3100
Ambiguous subinterfaces can also use the any keyword to specify the inner VLAN ID.
See the “Monitoring and Maintaining VLAN Subinterfaces” section on page 55 for an example of how VLAN IDs are assigned to subinterfaces, and for a detailed example of how the any keyword is used on ambiguous subinterfaces.
Only PPPoE is supported on ambiguous subinterfaces. Standard IP routing is not supported on ambiguous subinterfaces.
Note On the Cisco 10000 series Internet router, Modular QoS services are only supported on unambiguous subinterfaces.
Perform these tasks to configure the main interface used for the Q-in-Q double tagging and to configure the subinterfaces.
• Configuring EtherType Field for Outer VLAN Tag Termination, page 50 (Optional)
• Configuring the Q-in-Q Subinterface, page 50 (Required)
• Verifying the IEEE 802.1Q-in-Q VLAN Tag Termination, page 52 (Optional)
Prerequisites
For the Cisco 10000 series Internet router:
• PPPoE is already configured.
• Virtual private dial-up network (VPDN) is enabled.
The first task is optional. A step in this task shows you how to configure the EtherType field to be 0x9100 for the outer VLAN tag, if that is required.
After the subinterface is defined, the 802.1Q encapsulation is configured to use the double tagging.
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Configuring EtherType Field for Outer VLAN Tag Termination
To configure the EtherType field for Outer VLAN Tag Termination, use the following steps. This task is optional.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. dot1q tunneling ethertype ethertype
DETAILED STEPS
Configuring the Q-in-Q Subinterface
Use the following steps to configure Q-in-Q subinterfaces. This task is required.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number.subinterface-number
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface type number
Example:Router(config)# interface gigabitethernet 1/0/0
Configures an interface and enters interface configuration mode.
Step 4 dot1q tunneling ethertype ethertype
Example:Router(config-if)# dot1q tunneling ethertype 0x9100
(Optional) Defines the Ethertype field type used by peer devices when implementing Q-in-Q VLAN tagging.
• Use this command if the Ethertype of peer devices is 0x9100 or 0x9200 (0x9200 is only supported on the Cisco 10000 series Internet router).
• Cisco 10000 series Internet router supports both the 0x9100 and 0x9200 Ethertype field types.
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4. encapsulation dot1q vlan-id second-dot1q {any | vlan-id | vlan-id-vlan-id [,vlan-id-vlan-id]}
5. pppoe enabled [group group-name]
6. exit
7. Repeat Step 3 to configure another subinterface.
8. Repeat Step 4 and Step 5 to specify the VLAN tags to be terminated on the subinterface and to enable PPPoE sessions on the subinterface.
9. end
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface type number.subinterface-number
Example:Router(config-if)# interface gigabitethernet 1/0/0.1
Configures a subinterface and enters subinterface configuration mode.
Step 4 encapsulation dot1q vlan-id second-dot1q {any | vlan-id | vlan-id-vlan-id[,vlan-id-vlan-id]}
Example:Router(config-subif)# encapsulation dot1q 100 second-dot1q 200
(Required) Enables the 802.1Q encapsulation of traffic on a specified subinterface in a VLAN.
• Use the second-dot1q keyword and the vlan-id argument to specify the VLAN tags to be terminated on the subinterface.
• In this example, an unambiguous Q-in-Q subinterface is configured because only one inner VLAN ID is specified.
• Q-in-Q frames with an outer VLAN ID of 100 and an inner VLAN ID of 200 will be terminated.
Step 5 pppoe enable [group group-name]
Example:Router(config-subif)# pppoe enable group vpn1
Enables PPPoE sessions on a subinterface.
• The example specifies that the PPPoE profile, vpn1, will be used by PPPoE sessions on the subinterface.
Step 6 exit
Example:Router(config-subif)# exit
Exits subinterface configuration mode and returns to interface configuration mode.
• Repeat this step one more time to exit interface configuration mode.
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Verifying the IEEE 802.1Q-in-Q VLAN Tag Termination
Perform this optional task to verify the configuration of the IEEE 802.1Q-in-Q VLAN Tag Termination feature.
SUMMARY STEPS
1. enable
2. show running-config
3. show vlans dot1q [internal | interface-type interface-number.subinterface-number [detail] | outer-id [interface-type interface-number | second-dot1q [inner-id | any]] [detail]]
DETAILED STEPS
Step 1 enable
Enables privileged EXEC mode. Enter your password if prompted.
Step 7 Repeat Step3 to configure another subinterface.
Example:Router(config-if)# interface gigabitethernet 1/0/0.2
(Optional) Configures a subinterface and enters subinterface configuration mode.
Step 8 Repeat Step 4 and Step 5 to specify the VLAN tags to be terminated on the subinterface.
Example:Router(config-subif)# encapsulation dot1q 100 second-dot1q 100-199,201-600
Example:Router(config-subif)# pppoe enable group vpn1
Step 4 enables the 802.1Q encapsulation of traffic on a specified subinterface in a VLAN.
• Use the second-dot1q keyword and the vlan-id argument to specify the VLAN tags to be terminated on the subinterface.
• In the example, an ambiguous Q-in-Q subinterface is configured because a range of inner VLAN IDs is specified.
• Q-in-Q frames with an outer VLAN ID of 100 and an inner VLAN ID in the range of 100 to 199 or 201 to 600 will be terminated.
Step 5 enables PPPoE sessions on the subinterface. The example specifies that the PPPoE profile, vpn1, will be used by PPPoE sessions on the subinterface.
Note Step 5 is required for the Cisco 10000 series Internet router because it only supports PPPoEoQinQ traffic.
Step 9 end
Example:Router(config-subif)# end
Exits subinterface configuration mode and returns to privileged EXEC mode.
Command or Action Purpose
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Router> enable
Step 2 show running-config
Use this command to show the currently running configuration on the device. You can use delimiting characters to display only the relevant parts of the configuration.
The following shows the currently running configuration on a Cisco 7300 series router:
Router# show running-config
.
.
.
interface FastEthernet0/0.201 encapsulation dot1Q 201 ip address 10.7.7.5 255.255.255.252!interface FastEthernet0/0.401 encapsulation dot1Q 401 ip address 10.7.7.13 255.255.255.252!interface FastEthernet0/0.201999 encapsulation dot1Q 201 second-dot1q any pppoe enable!interface FastEthernet0/0.2012001 encapsulation dot1Q 201 second-dot1q 2001 ip address 10.8.8.9 255.255.255.252!interface FastEthernet0/0.2012002 encapsulation dot1Q 201 second-dot1q 2002 ip address 10.8.8.13 255.255.255.252!interface FastEthernet0/0.4019999 encapsulation dot1Q 401 second-dot1q 100-900,1001-2000 pppoe enable!interface GigabitEthernet5/0.101 encapsulation dot1Q 101 ip address 10.7.7.1 255.255.255.252!interface GigabitEthernet5/0.301 encapsulation dot1Q 301 ip address 10.7.7.9 255.255.255.252!interface GigabitEthernet5/0.301999 encapsulation dot1Q 301 second-dot1q any pppoe enable!interface GigabitEthernet5/0.1011001 encapsulation dot1Q 101 second-dot1q 1001 ip address 10.8.8.1 255.255.255.252!interface GigabitEthernet5/0.1011002 encapsulation dot1Q 101 second-dot1q 1002 ip address 10.8.8.5 255.255.255.252!interface GigabitEthernet5/0.1019999 encapsulation dot1Q 101 second-dot1q 1-1000,1003-2000 pppoe enable
.
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.
.
The following shows the currently running configuration on a Cisco 10000 series Internet router:
Router# show running-config
.
.
.
interface FastEthernet1/0/0.201 encapsulation dot1Q 201 ip address 10.7.7.5 255.255.255.252!interface FastEthernet1/0/0.401 encapsulation dot1Q 401 ip address 10.7.7.13 255.255.255.252!interface FastEthernet1/0/0.201999 encapsulation dot1Q 201 second-dot1q any pppoe enable!interface FastEthernet1/0/0.4019999 encapsulation dot1Q 401 second-dot1q 100-900,1001-2000 pppoe enable!interface GigabitEthernet5/0/0.101 encapsulation dot1Q 101 ip address 10.7.7.1 255.255.255.252!interface GigabitEthernet5/0/0.301 encapsulation dot1Q 301 ip address 10.7.7.9 255.255.255.252!interface GigabitEthernet5/0/0.301999 encapsulation dot1Q 301 second-dot1q any pppoe enable!interface GigabitEthernet5/0/0.1019999 encapsulation dot1Q 101 second-dot1q 1-1000,1003-2000 pppoe enable
.
.
.
Step 3 show vlans dot1q [internal | interface-type interface-number.subinterface-number [detail] | outer-id [interface-type interface-number | second-dot1q [inner-id | any]] [detail]]
Use this command to show the statistics for all the 802.1Q VLAN IDs. In this example, only the outer VLAN ID is displayed.
Note The show vlans dot1q command is not supported on the Cisco 10000 series Internet router.
Router# show vlans dot1q
Total statistics for 802.1Q VLAN 1: 441 packets, 85825 bytes input 1028 packets, 69082 bytes outputTotal statistics for 802.1Q VLAN 101: 5173 packets, 510384 bytes input 3042 packets, 369567 bytes output
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Total statistics for 802.1Q VLAN 201: 1012 packets, 119254 bytes input 1018 packets, 120393 bytes outputTotal statistics for 802.1Q VLAN 301: 3163 packets, 265272 bytes input 1011 packets, 120750 bytes outputTotal statistics for 802.1Q VLAN 401: 1012 packets, 119254 bytes input 1010 packets, 119108 bytes output
Monitoring and Maintaining VLAN SubinterfacesUse the following task to determine whether a VLAN is a native VLAN.
SUMMARY STEPS
1. enable
2. configure terminal
3. show vlans
DETAILED STEPS
Example
The following is sample output from the show vlans command indicating a native VLAN and a bridged group:
Router# show vlans
Virtual LAN ID: 1 (IEEE 802.1Q Encapsulation)
vLAN Trunk Interface: FastEthernet1/0/2
This is configured as native Vlan for the following interface(s) :
FastEthernet1/0/2
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 show vlans
Example:Router# show vlans
Displays VLAN subinterfaces.
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Protocols Configured: Address: Received: Transmitted:
Virtual LAN ID: 100 (IEEE 802.1Q Encapsulation)
vLAN Trunk Interface: FastEthernet1/0/2.1
Protocols Configured: Address: Received: Transmitted:
Bridging Bridge Group 1 0 0
The following is sample output from the show vlans command that shows the traffic count on Fast Ethernet subinterfaces:
Router# show vlans
Virtual LAN ID: 2 (IEEE 802.1Q Encapsulation)
vLAN Trunk Interface: FastEthernet5/0.1 Protocols Configured: Address: Received: Transmitted: IP 172.16.0.3 16 92129 Virtual LAN ID: 3 (IEEE 802.1Q Encapsulation) vLAN Trunk Interface: Ethernet6/0/1.1 Protocols Configured: Address: Received: Transmitted: IP 172.20.0.3 1558 1521 Virtual LAN ID: 4 (Inter Switch Link Encapsulation) vLAN Trunk Interface: FastEthernet5/0.2 Protocols Configured: Address: Received: Transmitted: IP 172.30.0.3 0 7
Configuration Examples for Configuring Routing Between VLANs
This section provides the following configuration example:
• Single Range Configuration: Example, page 56
• ISL Encapsulation Configuration: Examples, page 57
• Routing IEEE 802.10 Configuration: Example, page 67
• IEEE 802.1Q Encapsulation Configuration: Examples, page 68
• Configuring IEEE 802.1Q-in-Q VLAN Tag Termination: Example, page 72
Single Range Configuration: ExampleThe following example configures the Fast Ethernet subinterfaces within the range 5/1.1 and 5/1.4 and applies the following VLAN IDs to those subinterfaces:
Fast Ethernet5/1.1 = VLAN ID 301 (vlan-id)
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Fast Ethernet5/1.2 = VLAN ID 302 (vlan-id = 301 + 2 – 1 = 302)
Fast Ethernet5/1.3 = VLAN ID 303 (vlan-id = 301 + 3 – 1 = 303)
Fast Ethernet5/1.4 = VLAN ID 304 (vlan-id = 301 + 4 – 1 = 304)
Router(config)# interface range fastethernet5/1.1 - fastethernet5/1.4 Router(config-if)# encapsulation dot1Q 301Router(config-if)# no shutdown Router(config-if)#*Oct 6 08:24:35: %LINK-3-UPDOWN: Interface FastEthernet5/1.1, changed state to up*Oct 6 08:24:35: %LINK-3-UPDOWN: Interface FastEthernet5/1.2, changed state to up*Oct 6 08:24:35: %LINK-3-UPDOWN: Interface FastEthernet5/1.3, changed state to up*Oct 6 08:24:35: %LINK-3-UPDOWN: Interface FastEthernet5/1.4, changed state to up*Oct 6 08:24:36: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet5/1.1, changed state to up*Oct 6 08:24:36: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet5/1.2, changed state to up*Oct 6 08:24:36: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet5/1.3, changed state to up*Oct 6 08:24:36: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet5/1.4, changed state to up
ISL Encapsulation Configuration: ExamplesThis section provides the following configuration examples for each of the protocols described in this chapter:
• AppleTalk Routing over ISL Configuration: Example, page 58
• Banyan VINES Routing over ISL Configuration: Example, page 59
• DECnet Routing over ISL Configuration: Example, page 59
• HSRP over ISL Configuration: Example, page 59
• IP Routing with RIF Between TrBRF VLANs: Example, page 61
• IP Routing Between a TRISL VLAN and an Ethernet ISL VLAN: Example, page 62
• IPX Routing over ISL Configuration: Example, page 62
• IPX Routing on FDDI Interfaces with SDE: Example, page 64
• Routing with RIF Between a TRISL VLAN and a Token Ring Interface: Example, page 64
• VIP Distributed Switching over ISL Configuration: Example, page 65
• XNS Routing over ISL Configuration: Example, page 66
• CLNS Routing over ISL Configuration: Example, page 66
• IS-IS Routing over ISL Configuration: Example
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AppleTalk Routing over ISL Configuration: Example
The configuration example illustrated in Figure 12 shows AppleTalk being routed between different ISL and IEEE 802.10 VLAN encapsulating subinterfaces.
Figure 12 Routing AppleTalk over VLAN Encapsulations
As shown in Figure 12, AppleTalk traffic is routed to and from switched VLAN domains 3, 4, 100, and 200 to any other AppleTalk routing interface. This example shows a sample configuration file for the Cisco 7500 series router with the commands entered to configure the network shown in Figure 12.
Cisco 7500 Router Configuration!appletalk routinginterface Fddi 1/0.100 encapsulation sde 100 appletalk cable-range 100-100 100.2 appletalk zone 100!interface Fddi 1/0.200 encapsulation sde 200 appletalk cable-range 200-200 200.2 appletalk zone 200!interface FastEthernet 2/0.3encapsulation isl 3
appletalk cable-range 3-3 3.2 appletalk zone 3!interface FastEthernet 2/0.4encapsulation isl 4
appletalk cable-range 4-4 4.2 appletalk zone 4!
Wide-area linkCisco 7500
series router
Catalyst 5000 switchsupporting 2 AppleTalk
VLANs on FastEthernetconnections with ISL
encapsulation
FastEthernet 2/0100BASE-T ISL
VLAN 4Apple 4.1
VLAN 3Apple 3.1
Apple 100.1VLAN 100 FDDI VLAN backbone using
802.10 encapsulation format
FDDI SDEfddi 1/0
Apple 200.1VLAN 200
Catalyst 1200
S62
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Banyan VINES Routing over ISL Configuration: Example
To configure routing of the Banyan VINES protocol over ISL trunks, you need to define ISL as the encapsulation type. This example shows Banyan VINES configured to be routed over an ISL trunk:
vines routinginterface fastethernet 0.1encapsulation isl 100vines metric 2
DECnet Routing over ISL Configuration: Example
To configure routing the DECnet protocol over ISL trunks, you need to define ISL as the encapsulation type. This example shows DECnet configured to be routed over an ISL trunk:
decnet routing 2.1interface fastethernet 1/0.1encapsulation isl 200decnet cost 4
HSRP over ISL Configuration: Example
The configuration example shown in Figure 13 shows HSRP being used on two VLAN routers sending traffic to and from ISL VLANs through a Catalyst 5000 switch. Each router forwards its own traffic and acts as a standby for the other.
Figure 13 Hot Standby Router Protocol Sample Configuration
The topology shown in Figure 13 shows a Catalyst VLAN switch supporting Fast Ethernet connections to two routers running HSRP. Both routers are configured to route HSRP over ISLs.
S62
39
Enterprisenetwork
HSRP peers
FE 1/1FE 1/1
Port 2/8
Port 5/3
Port 2/9
Port 5/4
ISL VLAN 110
Catalyst VLANswitch
Ethernet 1/2
Ethernet 1/2
Ethernet 1/2
Ethernet 1/2
Host 1 Host 2
Cisco IOS Router Aon FastEthernet
ISL connection to aCatalyst 5000 switch
Cisco IOS Router Bon FastEthernetISL connection to aCatalyst 5000 switch
Cisco IOSCisco IOS
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The standby conditions are determined by the standby commands used in the configuration. Traffic from Host 1 is forwarded through Router A. Because the priority for the group is higher, Router A is the active router for Host 1. Because the priority for the group serviced by Host 2 is higher in Router B, traffic from Host 2 is forwarded through Router B, making Router B its active router.
In the configuration shown in Figure 13, if the active router becomes unavailable, the standby router assumes active status for the additional traffic and automatically routes the traffic normally handled by the router that has become unavailable.
Host 1 Configurationinterface Ethernet 1/2ip address 10.1.1.25 255.255.255.0ip route 0.0.0.0 0.0.0.0 10.1.1.101
Host 2 Configurationinterface Ethernet 1/2ip address 10.1.1.27 255.255.255.0ip route 0.0.0.0 0.0.0.0 10.1.1.102
!
Router A Configurationinterface FastEthernet 1/1.110encapsulation isl 110ip address 10.1.1.2 255.255.255.0standby 1 ip 10.1.1.101standby 1 preemptstandby 1 priority 105standby 2 ip 10.1.1.102standby 2 preempt
!end
!
Router B Configurationinterface FastEthernet 1/1.110encapsulation isl 110ip address 10.1.1.3 255.255.255.0standby 1 ip 10.1.1.101standby 1 preemptstandby 2 ip 10.1.1.102standby 2 preemptstandby 2 priority 105
router igrp 1!network 10.1.0.0network 10.2.0.0!
VLAN Switch Configurationset vlan 110 5/4set vlan 110 5/3set trunk 2/8 110set trunk 2/9 110
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IP Routing with RIF Between TrBRF VLANs: Example
Figure 14 shows IP routing with RIF between two TrBRF VLANs.
Figure 14 IP Routing with RIF Between TrBRF VLANs
The following is the configuration for the router:
interface FastEthernet4/0.1ip address 10.5.5.1 255.255.255.0encapsulation tr-isl trbrf-vlan 999 bridge-num 14multiring trcrf-vlan 200 ring 100multiring all
!interface FastEthernet4/0.2ip address 10.4.4.1 255.255.255.0encapsulation tr-isl trbrf-vlan 998 bridge-num 13multiring trcrf-vlan 300 ring 101multiring all
The following is the configuration for the Catalyst 5000 switch with the Token Ring switch module in slot 5. In this configuration, the Token Ring port 102 is assigned with TrCRF VLAN 40 and the Token Ring port 103 is assigned with TrCRF VLAN 50:
#vtpset vtp domain trislset vtp mode serverset vtp v2 enable#dripset set tokenring reduction enableset tokenring distrib-crf disable#vlansset vlan 999 name trbrf type trbrf bridge 0xe stp ieeeset vlan 200 name trcrf200 type trcrf parent 999 ring 0x64 mode srbset vlan 40 name trcrf40 type trcrf parent 999 ring 0x66 mode srbset vlan 998 name trbrf type trbrf bridge 0xd stp ieeeset vlan 300 name trcrf300 type trcrf parent 998 ring 0x65 mode srbset vlan 50 name trcrf50 type trcrf parent 998 ring 0x67 mode srb#add token port to trcrf 40set vlan 40 5/1#add token port to trcrf 50set vlan 50 5/2set trunk 1/2 on
Catalyst5000 switch
5500
1125
0
End station
TokenRing103
End station
TrBRF 998 / Bridge 13
TrBRF 999 / Bridge 14Router
101
100
TokenRing102
Fast Ethernet 4/0.1
Fast Ethernet 4/0.2
Token Ringswitch module
5.5.5.1
4.4.4.1
TrCRF VLAN 40Slot 5Port 1
TrCRF VLAN 50Slot 5Port 2
TrCRF 300
TrCRF 200
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IP Routing Between a TRISL VLAN and an Ethernet ISL VLAN: Example
Figure 15 shows IP routing between a TRISL VLAN and an Ethernet ISL VLAN.
Figure 15 IP Routing Between a TRISL VLAN and an Ethernet ISL VLAN
The following is the configuration for the router:
interface FastEthernet4/0.1ip address 10.5.5.1 255.255.255.0encapsulation tr-isl trbrf-vlan 999 bridge-num 14multiring trcrf-vlan 20 ring 100multiring all
!interface FastEthernet4/0.2ip address 10.4.4.1 255.255.255.0encapsulation isl 12
IPX Routing over ISL Configuration: Example
Figure 16 shows IPX interior encapsulations configured over ISL encapsulation in VLAN configurations. Note that three different IPX encapsulation formats are used. VLAN 20 uses SAP encapsulation, VLAN 30 uses ARPA, and VLAN 70 uses novell-ether encapsulation. Prior to the introduction of this feature, only the default encapsulation format, “novell-ether,” was available for routing IPX over ISL links in VLANs.
End station
End station
Ethernet ISL VLAN 12
5.5.5.1
4.4.4.1
TrBRF 999 / Bridge 14
Router A
1125
1
Token Ring switch modulein slot 5
TrCRF100Slot 5Port 1
Ethernetmodulein slot 2
Catalyst5000 switch
5500
TokenRing
1100
TrCRF 200
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Figure 16 Configurable IPX Encapsulations Routed over ISL in VLAN Configurations
VLAN 20 Configuration ipx routinginterface FastEthernet 2/0 no shutdown
interface FastEthernet 2/0.20encapsulation isl 20ipx network 20 encapsulation sap
VLAN 30 Configurationipx routinginterface FastEthernet 2/0 no shutdown
interface FastEthernet 2/0.30encapsulation isl 30ipx network 30 encapsulation arpa
VLAN 70 Configurationipx routinginterface FastEthernet 3/0no shutdown
interface Fast3/0.70encapsulation isl 70ipx network 70 encapsulation novell-ether
Wide-area linkcarrying VLAN traffic
Workstation Con an IPX LAN
with novell-etherencapsulation
VLAN 70VLAN 20
VLAN 30
FE 2/0
Catalyst5000 switch
Catalyst2900 switch
FE 3/0
Fast Ethernet linkscarrying ISL traffic
Workstation Arunning NetWare 4.0on an IPX LAN withsap encapsulation
Workstation Bon an IPX LAN witharpa encapsulation S
6240
Cisco 7200 routerrunning traffic
between VLANsRSP
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IPX Routing on FDDI Interfaces with SDE: Example
The following example enables IPX routing on FDDI interfaces 0.2 and 0.3 with SDE. On FDDI interface 0.2, the encapsulation type is SNAP. On FDDI interface 0.3, the encapsulation type is Novell’s FDDI_RAW.
ipx routing
interface fddi 0.2 enc sde 2ipx network f02 encapsulation snap
interface fddi 0.3 enc sde 3ipx network f03 encapsulation novell-fddi
Routing with RIF Between a TRISL VLAN and a Token Ring Interface: Example
Figure 17 shows routing with RIF between a TRISL VLAN and a Token Ring interface.
Figure 17 Routing with RIF Between a TRISL VLAN and a Token Ring Interface
The following is the configuration for the router:
source-bridge ring-group 100!interface TokenRing 3/1ip address 10.4.4.1 255.255.255.0
!interface FastEthernet4/0.1ip address 10.5.5.1 255.255.255.0encapsulation tr-isl trbrf 999 bridge-num 14multiring trcrf-vlan 200 ring-group 100multiring all
The following is the configuration for the Catalyst 5000 switch with the Token Ring switch module in slot 5. In this configuration, the Token Ring port 1 is assigned to the TrCRF VLAN 40:
#vtpset vtp domain trislset vtp mode serverset vtp v2 enable#drip
1077
7
Fast Ethernet 4/0.1
5.5.5.14.4.4.1
100
Catalyst 5000 switch
5500Token Ringswitchmodule
TrCRF VLAN 40Slot 5Port 1
TrBRF 999 / Bridge 14TrCRF 200
End station
TokenRing 1
End station
End station
End station
TokenRing 2
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set set tokenring reduction enableset tokenring distrib-crf disable#vlansset vlan 999 name trbrf type trbrf bridge 0xe stp ieeeset vlan 200 name trcrf200 type trcrf parent 999 ring 0x64 mode srtset vlan 40 name trcrf40 type trcrf parent 999 ring 0x1 mode srt#add token port to trcrf 40set vlan 40 5/1set trunk 1/2 on
VIP Distributed Switching over ISL Configuration: Example
Figure 18 shows a topology in which Catalyst VLAN switches are connected to routers forwarding traffic from a number of ISL VLANs. With the VIP distributed ISL capability in the Cisco 7500 series router, each VIP card can route ISL-encapsulated VLAN IP traffic. The inter-VLAN routing capacity is increased linearly by the packet-forwarding capability of each VIP card.
Figure 18 VIP Distributed ISL VLAN Traffic
In Figure 18, the VIP cards forward the traffic between ISL VLANs or any other routing interface. Traffic from any VLAN can be routed to any of the other VLANs, regardless of which VIP card receives the traffic.
These commands show the configuration for each of the VLANs shown in Figure 18:
interface FastEthernet1/0/0 ip address 10.1.1.1 255.255.255.0 ip route-cache distributed full-duplex
FE
VIP
CyBus
Fast Ethernetport adapters
Cisco 7500 series router withVIP2 or later cards routing
traffic between VLANs
Catalyst VLANswitches forwardingISL VLAN traffic
FE FEFE
S62
38ISL VLAN 1 ISL VLAN 2 ISL VLAN 3 ISL VLAN 4 ISL VLAN 5
WAN
ISL VLAN 6 ISL VLAN 7
Fast Ethernet linkscarrying ISL VLAN traffic
RSP
VIP
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interface FastEthernet1/0/0.1 ip address 10.1.1.1 255.255.255.0 encapsulation isl 1
interface FastEthernet1/0/0.2 ip address 10.1.2.1 255.255.255.0 encapsulation isl 2
interface FastEthernet1/0/0.3 ip address 10.1.3.1 255.255.255.0 encapsulation isl 3
interface FastEthernet1/1/0 ip route-cache distributed full-duplex
interface FastEthernet1/1/0.1 ip address 172.16.1.1 255.255.255.0 encapsulation isl 4
interface Fast Ethernet 2/0/0ip address 10.1.1.1 255.255.255.0ip route-cache distributedfull-duplex
interface FastEthernet2/0/0.5 ip address 10.2.1.1 255.255.255.0 encapsulation isl 5
interface FastEthernet2/1/0 ip address 10.3.1.1 255.255.255.0 ip route-cache distributed full-duplex
interface FastEthernet2/1/0.6 ip address 10.4.6.1 255.255.255.0 encapsulation isl 6
interface FastEthernet2/1/0.7 ip address 10.4.7.1 255.255.255.0 encapsulation isl 7
XNS Routing over ISL Configuration: Example
To configure routing of the XNS protocol over ISL trunks, you need to define ISL as the encapsulation type. This example shows XNS configured to be routed over an ISL trunk:
xns routing 0123.4567.adcbinterface fastethernet 1/0.1encapsulation isl 100xns network 20
CLNS Routing over ISL Configuration: Example
To configure routing of the CLNS protocol over ISL trunks, you need to define ISL as the encapsulation type. This example shows CLNS configured to be routed over an ISL trunk:
clns routing interface fastethernet 1/0.1
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encapsulation isl 100clns enable
IS-IS Routing over ISL Configuration: Example
To configure IS-IS routing over ISL trunks, you need to define ISL as the encapsulation type. This example shows IS-IS configured over an ISL trunk:
isis routing test-proc2net 49.0001.0002.aaaa.aaaa.aaaa.00interface fastethernet 2.0encapsulation isl 101clns router is-is test-proc2
Routing IEEE 802.10 Configuration: ExampleThe configuration example shown in Figure 19 shows AppleTalk being routed between different ISL and IEEE 802.10 VLAN encapsulating subinterfaces.
Figure 19 Routing AppleTalk over VLAN encapsulations
As shown in Figure 19, AppleTalk traffic is routed to and from switched VLAN domains 3, 4, 100, and 200 to any other AppleTalk routing interface. This example shows a sample configuration file for the Cisco 7500 series router with the commands entered to configure the network shown in Figure 19.
Cisco 7500 Router Configuration!interface Fddi 1/0.100 encapsulation sde 100 appletalk cable-range 100-100 100.2 appletalk zone 100!
Wide-area linkCisco 7500
series router
Catalyst 5000 switchsupporting 2 AppleTalk
VLANs on FastEthernetconnections with ISL
encapsulation
FastEthernet 2/0100BASE-T ISL
VLAN 4Apple 4.1
VLAN 3Apple 3.1
Apple 100.1VLAN 100 FDDI VLAN backbone using
802.10 encapsulation format
FDDI SDEfddi 1/0
Apple 200.1VLAN 200
Catalyst 1200
S62
41
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interface Fddi 1/0.200 encapsulation sde 200 appletalk cable-range 200-200 200.2 appletalk zone 200!interface FastEthernet 2/0.3encapsulation isl 3
appletalk cable-range 3-3 3.2 appletalk zone 3!interface FastEthernet 2/0.4encapsulation isl 4
appletalk cable-range 4-4 4.2 appletalk zone 4!
IEEE 802.1Q Encapsulation Configuration: ExamplesConfiguration examples for each protocols are provided in the following sections:
• !Configuring AppleTalk over IEEE 802.1Q: Example, page 68
• Configuring IP Routing over IEEE 802.1Q: Example, page 68
• Configuring IPX Routing over IEEE 802.1Q: Example, page 69
• VLAN 100 for Bridge Group 1 with Default VLAN1: Example, page 69
• VLAN 20 for Bridge Group 1 with Native VLAN: Example, page 69
• VLAN ISL or IEEE 802.1Q Routing: Example, page 69
• VLAN IEEE 802.1Q Bridging: Example, page 70
• VLAN IEEE 802.1Q IRB: Example, page 71
Configuring AppleTalk over IEEE 802.1Q: Example
This configuration example shows AppleTalk being routed on VLAN 100:
!appletalk routing!interface fastethernet 4/1.100
encapsulation dot1q 100appletalk cable-range 100-100 100.1appletalk zone eng
!
Configuring IP Routing over IEEE 802.1Q: Example
This configuration example shows IP being routed on VLAN 101:
!ip routing!interface fastethernet 4/1.101
encapsulation dot1q 101ip addr 10.0.0.11 255.0.0.0
!
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Configuring IPX Routing over IEEE 802.1Q: Example
This configuration example shows IPX being routed on VLAN 102:
!ipx routing!interface fastethernet 4/1.102
encapsulation dot1q 102ipx network 100
!
VLAN 100 for Bridge Group 1 with Default VLAN1: Example
The following example configures VLAN 100 for bridge group 1 with a default VLAN1:
interface FastEthernet 4/1.100encapsulation dot1q 1bridge-group 1
VLAN 20 for Bridge Group 1 with Native VLAN: Example
The following example configures VLAN 20 for bridge group 1 as a native VLAN:
interface FastEthernet 4/1.100encapsulation dot1q 20 nativebridge-group 1
VLAN ISL or IEEE 802.1Q Routing: Example
The following example configures VLAN ISL or IEEE 802.10 routing:
ipx routingappletalk routing!interface Ethernet 1ip address 10.1.1.1 255.255.255.0appletalk cable-range 1-1 1.1appletalk zone 1ipx network 10 encapsulation snap!router igrp 1network 10.1.0.0!end!#Catalyst5000!set VLAN 110 2/1set VLAN 120 2/2!set trunk 1/1 110,120# if 802.1Q, set trunk 1/1 nonegotiate 110, 120!end!
ipx routingappletalk routing!interface FastEthernet 1/1.110
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encapsulation isl 110!if 802.1Q, encapsulation dot1Q 110ip address 10.1.1.2 255.255.255.0appletalk cable-range 1.1 1.2appletalk zone 1ipx network 110 encapsulation snap!interface FastEthernet 1/1.120encapsulation isl 120!if 802.1Q, encapsulation dot1Q 120ip address 10.2.1.2 255.255.255.0appletalk cable-range 2-2 2.2appletalk zone 2ipx network 120 encapsulation snap!router igrp 1network 10.1.0.0network 10.2.1.0.0!end!
ipx routingappletalk routing!interface Ethernet 1ip address 10.2.1.3 255.255.255.0appletalk cable-range 2-2 2.3appletalk zone 2ipx network 120 encapsulation snap!router igrp 1network 10.2.0.0!end
VLAN IEEE 802.1Q Bridging: Example
The following examples configures IEEE 802.1Q bridging:
interface FastEthernet4/0 no ip address no ip route-cache half-duplex!interface FastEthernet4/0.100 encapsulation dot1Q 100 no ip route-cache bridge-group 1!interface FastEthernet4/0.200 encapsulation dot1Q 200 native no ip route-cache bridge-group 2!interface FastEthernet4/0.300 encapsulation dot1Q 1 no ip route-cache bridge-group 3!interface FastEthernet10/0 no ip address no ip route-cache
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half-duplex!interface FastEthernet10/0.100 encapsulation dot1Q 100 no ip route-cache bridge-group 1!interface Ethernet11/3 no ip address no ip route-cache bridge-group 2!interface Ethernet11/4 no ip address no ip route-cache bridge-group 3!bridge 1 protocol ieeebridge 2 protocol ieeebridge 3 protocol ieee
VLAN IEEE 802.1Q IRB: Example
The following examples configures IEEE 802.1Q integrated routing and bridging:
ip cefappletalk routingipx routing 0060.2f27.5980!bridge irb!interface TokenRing3/1 no ip address ring-speed 16 bridge-group 2!interface FastEthernet4/0 no ip address half-duplex!interface FastEthernet4/0.100 encapsulation dot1Q 100 bridge-group 1!interface FastEthernet4/0.200 encapsulation dot1Q 200 bridge-group 2!interface FastEthernet10/0ip address 10.3.1.10 255.255.255.0 half-duplex appletalk cable-range 200-200 200.10 appletalk zone irb ipx network 200!interface Ethernet11/3 no ip address bridge-group 1!interface BVI 1 ip address 10.1.1.11 255.255.255.0 appletalk cable-range 100-100 100.11 appletalk zone bridging
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ipx network 100!router rip network 10.0.0.0 network 10.3.0.0!bridge 1 protocol ieee bridge 1 route appletalk bridge 1 route ip bridge 1 route ipxbridge 2 protocol ieee!
Configuring IEEE 802.1Q-in-Q VLAN Tag Termination: ExampleSome ambiguous subinterfaces can use the any keyword for the inner VLAN ID specification. The any keyword represents any inner VLAN ID that is not explicitly configured on any other interface. In the following example, seven subinterfaces are configured with various outer and inner VLAN IDs.
Note The any keyword can be configured on only one subinterface of a specified physical interface and outer VLAN ID.
interface GigabitEthernet1/0/0.1 encapsulation dot1q 100 second-dot1q 100
interface GigabitEthernet1/0/0.2 encapsulation dot1q 100 second-dot1q 200
interface GigabitEthernet1/0/0.3 encapsulation dot1q 100 second-dot1q 300-400,500-600
interface GigabitEthernet1/0/0.4 encapsulation dot1q 100 second-dot1q any
interface GigabitEthernet1/0/0.5 encapsulation dot1q 200 second-dot1q 50
interface GigabitEthernet1/0/0.6 encapsulation dot1q 200 second-dot1q 1000-2000,3000-4000
interface GigabitEthernet1/0/0.7 encapsulation dot1q 200 second-dot1q any
Table 5 shows which subinterfaces are mapped to different values of the outer and inner VLAN ID on Q-in-Q frames that come in on Gigabit Ethernet interface 1/0/0.
Table 5 Subinterfaces Mapped to Outer and Inner VLAN IDs for GE Interface 1/0/0
Outer VLAN ID Inner VLAN ID Subinterface mapped to
100 1 through 99 GigabitEthernet1/0/0.4
100 100 GigabitEthernet1/0/0.1
100 101 through 199 GigabitEthernet1/0/0.4
100 200 GigabitEthernet1/0/0.2
100 201 through 299 GigabitEthernet1/0/0.4
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A new subinterface is now configured:
interface GigabitEthernet1/0/0.8 encapsulation dot1q 200 second-dot1q 200-600,900-999
Table 6 shows the changes made to the table for the outer VLAN ID of 200. Notice that subinterface 1/0/0.7 configured with the any keyword now has new inner VLAN ID mappings.
100 300 through 400 GigabitEthernet1/0/0.3
100 401 through 499 GigabitEthernet1/0/0.4
100 500 through 600 GigabitEthernet1/0/0.3
100 601 through 4095 GigabitEthernet1/0/0.4
200 1 through 49 GigabitEthernet1/0/0.7
200 50 GigabitEthernet1/0/0.5
200 51 through 999 GigabitEthernet1/0/0.7
200 1000 through 2000 GigabitEthernet1/0/0.6
200 2001 through 2999 GigabitEthernet1/0/0.7
200 3000 through 4000 GigabitEthernet1/0/0.6
200 4001 through 4095 GigabitEthernet1/0/0.7
Table 5 Subinterfaces Mapped to Outer and Inner VLAN IDs for GE Interface 1/0/0 (continued)
Outer VLAN ID Inner VLAN ID Subinterface mapped to
Table 6 Subinterfaces Mapped to Outer and Inner VLAN IDs for GE Interface 1/0/0—Changes
Resulting from Configuring GE Subinterface 1/0/0.8
Outer VLAN ID Inner VLAN ID Subinterface mapped to
200 1 through 49 GigabitEthernet1/0/0.7
200 50 GigabitEthernet1/0/0.5
200 51 through 199 GigabitEthernet1/0/0.7
200 200 through 600 GigabitEthernet1/0/0.8
200 601 through 899 GigabitEthernet1/0/0.7
200 900 through 999 GigabitEthernet1/0/0.8
200 1000 through 2000 GigabitEthernet1/0/0.6
200 2001 through 2999 GigabitEthernet1/0/0.7
200 3000 through 4000 GigabitEthernet1/0/0.6
200 4001 through 4095 GigabitEthernet1/0/0.7
Configuring Routing Between VLANsAdditional References
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Additional ReferencesThe following sections provide references related to configuring a VLAN range.
Related Documents
Standards
MIBs
Related Topic Document Title
Configuring wide-area networking Cisco IOS Wide-Area Networking Configuration Guide, Release 12.2
Commands used in configuring wide-area networking Cisco IOS Wide-Area Networking Command Reference, Release 12.2
Configuring interface ranges Interface Range Specification, new feature document for Cisco IOS Release 12.1(5)T
Commands using in Configuring Routing Between VLANs with IEEE 802.10 Encapsulation
Cisco IOS Release 12.4, Cisco IOS Switching Services Command Reference
Configuring AppleTalk Cisco IOS AppleTalk and Novell IPX Configuration Guide
Commands using in Configuring Routing Between VLANs with IEEE 802.1Q Encapsulation
Cisco IOS Release 12.4, Cisco IOS Switching Services Command Reference
IP routing configuration Cisco IOS IP Routing Configuration Guide
Interface commands: complete command syntax, command mode, defaults, usage guidelines, and examples
Cisco IOS Interface and Hardware Component Command Reference, Release 12.3T
Interface configuration examples Cisco IOS Interface and Hardware Component Configuration Guide
Standard Title
IEEE 802.10 standard 802.10 Virtual LANs
IEEE 802.1Q standard 802.1Q Virtual LANs
MIB MIBs Link
• None To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
http://www.cisco.com/go/mibs
Configuring Routing Between VLANsAdditional References
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RFCs
Technical Assistance
RFC Title
None —
Description Link
The Cisco Technical Support website contains thousands of pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.
http://www.cisco.com/techsupport
Configuring Routing Between VLANsFeature Information for Routing Between VLANs
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Feature Information for Routing Between VLANsTable 7 lists the features in this module and provides links to specific configuration information. Only features that were introduced or modified in Cisco IOS Releases 12.0(3)S or a later release appear in the table.
Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.
Cisco IOS software images are specific to a Cisco IOS software release, a feature set, and a platform. Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Note Table 7 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.
Table 7 Feature Information for Routing Between VLANs
Feature Name Releases Feature Information
VLAN Range Using the VLAN Range feature, you can group VLAN subinterfaces together so that any command entered in a group applies to every subinterface within the group. This capability simplifies configurations and reduces command parsing.
12.0(7)XE The interface range command was introduced.
12.1(5)T The interface range command was integrated into Cisco IOS Release 12.1(5)T.
12.2(2)DD The interface range command was expanded to enable configuration of subinterfaces.
12.2(4)B The interface range command was integrated into Cisco IOS Release 12.2(4)B.
12.2(8)T The VLAN Range feature was integrated into Cisco IOS Release 12.2(8)T.
12.2(13)T This VLAN Range feature was integrated into Cisco IOS Release 12.2(13)T.
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Managed LAN Switch
The Managed LAN Switch feature enables the control of the four switch ports in Cisco 831, 836, and 837 routers. Each switch port is associated with a Fast Ethernet interface. The output of the command show controllers fastEthernet <1-4> displays the status of the selected switch port.
The Managed LAN Switch feature allows setting and display of the following parameters for each of the switch ports:
• Speed
• Duplex
It also allows display of the link state of a switch port—that is, whether a device is connected to that port or not.
Feature History for the Managed LAN Switch Feature
Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Contents• Information About Managed LAN Switch, page 78
• How to Enable Managed LAN Switch, page 78
• Configuration Examples for Managed LAN Switch, page 80
• Additional References, page 80
• Command Reference, page 81
Release Modification
12.3(2)XC This feature modifies the output of the command show controllers fastEthernet <1-4> to show the status of switch port.
Managed LAN SwitchInformation About Managed LAN Switch
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Information About Managed LAN SwitchTo configure the Managed LAN Switch feature, you should understand the following concept:
• LAN Switching, page 78
LAN SwitchingA LAN is a high-speed, fault-tolerant data network that supplies connectivity to a group of computers, printers, and other devices that are in close proximity to each other, as in an office building, a school or a home. LANs offer computer users many advantages, including shared access to devices and applications, file exchange between connected users, and communication between users via electronic mail and other applications.
For more information about LAN switching, refer to the following URL:
http://www.cisco.com/en/US/tech/tk389/tech_topology_and_network_serv_and_protocol_suite_home.html
How to Enable Managed LAN SwitchThis section contains the following procedure:
• Enabling Managed LAN Switch
Enabling Managed LAN SwitchTo enable Managed LAN Switch, perform the following steps:
SUMMARY STEPS
1. enable
2. interface fastEthernet
3. duplex auto
4. speed auto
5. end
Managed LAN SwitchHow to Enable Managed LAN Switch
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DETAILED STEPS
Verifying Managed LAN SwitchTo verify the Managed LAN Switch configuration, enter the show controllers fastEthernet <1-4> command in EXEC mode. The following sample output shows the status of switch port 1.
Router#show controllers fastEthernet 1!Interface FastEthernet1 MARVELL 88E6052Link is DOWNPort is undergoing Negotiation or Link downSpeed :Not set, Duplex :Not set!Switch PHY Registers:~~~~~~~~~~~~~~~~~~~~~
00 : 3100 01 : 7849 02 : 0141 03 : 0C1F 04 : 01E105 : 0000 06 : 0004 07 : 2001 08 : 0000 16 : 013017 : 0002 18 : 0000 19 : 0040 20 : 0000 21 : 0000!Switch Port Registers:~~~~~~~~~~~~~~~~~~~~~~Port Status Register [00] : 0800Switch Identifier Register [03] : 0520Port Control Register [04] : 007FRx Counter Register [16] : 000ATx Counter Register [17] : 0008!
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 interface fastEthernet interface-number
Example:Router(config)# interface fastEthernet
Configures a Fast Ethernet interface and enters interface configuration mode.
Step 3 duplex auto
Example:Router(config-if)# duplex auto
Enables LAN switching on the selected port with duplex setting in auto mode.
Step 4 speed auto
Example:Router(config-if)# speed auto
Enables LAN switching on the selected port with speed setting in auto mode.
Step 5 end
Example:Router(config-if)# end
Ends the current configuration session and returns to privileged EXEC mode.
Managed LAN SwitchConfiguration Examples for Managed LAN Switch
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Configuration Examples for Managed LAN SwitchThis section provides the following configuration example:
• Enabling Managed LAN Switch: Example
Enabling Managed LAN Switch: ExampleThe following example shows the Managed LAN Switch configured with duplex set to auto and full, speed set to auto and 100:
configure terminalEnter configuration commands, one per line. End with CNTL/Z.interface fastEthernet1no ip addressduplex autospeed auto!interface fastEthernet2no ip address duplex full <---------------- duplex setting of port 2
speed 100 <----------------- speed setting of port 2
! interface fastEthernet3no ip addressshutdown <-------------- shutting port 3
duplex autospeed auto!interface fastEthernet4no ip addressduplex autospeed auto!
Additional ReferencesThe following sections provide references related to the Managed LAN Switch feature.
Related Documents
Related Topic Document Title
Cisco IOS Release 12.3 Configuration Guides and Command References
Cisco IOS Release 12.3 Configuration Guides and Command References
Managed LAN SwitchCommand Reference
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Standards
MIBs
RFCs
Technical Assistance
Command ReferenceThe following modified commands are pertinent to this feature. To see the command pages for these commands and other commands used with this feature, go to the Cisco IOS Master Commands List, Release 12.4, at http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124mindx/124index.htm.
• show controllers fastEthernet
Standards Title
None —
MIBs MIBs Link
• None To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
http://www.cisco.com/go/mibs
RFCs Title
None —
Description Link
Technical Assistance Center (TAC) home page, containing 30,000 pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.
http://www.cisco.com/public/support/tac/home.shtml
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Cisco HWIC-4ESW and HWIC-D-9ESW EtherSwitch Interface Cards
First Published: May 17, 2005Last Updated: April 15, 2006
This document provides configuration tasks for the 4-port Cisco HWIC-4ESW and the 9-port Cisco HWIC-D-9ESW EtherSwitch high-speed WAN interface cards (HWICs) hardware feature supported on Cisco 1800 (modular), Cisco 2800, and Cisco 3800 series integrated services routers.
Cisco EtherSwitch HWICs are 10/100BASE-T Layer 2 Ethernet switches with Layer 3 routing capability. (Layer 3 routing is forwarded to the host and is not actually performed at the switch.) Traffic between different VLANs on a switch is routed through the router platform. Any one port on a Cisco EtherSwitch HWIC may be configured as a stacking port to link to another Cisco EtherSwitch HWIC or EtherSwitch network module in the same system. An optional power module can also be added to provide inline power for IP telephones. The HWIC-D-9ESW HWIC requires a double-wide card slot.
This hardware feature does not introduce any new or modified Cisco IOS commands.
Finding Feature Information in This Module
Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the “Feature Information for the Cisco HWIC-4ESW and the Cisco HWIC-D-9ESW EtherSwitch Cards” section on page 198.
Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
ContentsThe following sections provide information about the Cisco EtherSwitch HWICs.
• Prerequisites for EtherSwitch HWICs, page 84
• Restrictions for EtherSwitch HWICs, page 84
• Information About EtherSwitch HWICs, page 85
• How to Configure EtherSwitch HWICs, page 87
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• Configuration Examples for EtherSwitch HWICs, page 185
• Additional References, page 195
• Command Reference, page 197
Prerequisites for EtherSwitch HWICsThe following are prerequisites to configuring EtherSwitch HWICs:
• Configuration of IP routing. (Refer to the Cisco IOS IP Configuration Guide.)
• Use of the Cisco IOS T release, beginning with Release 12.3(8)T4 or later for Cisco HWIC-4ESW and Cisco HWIC-D-9ESW support. (Refer to the Cisco IOS documentation.)
Restrictions for EtherSwitch HWICsThe following restrictions apply to the Cisco HWIC-4ESW and the Cisco HWIC-D-9ESW EtherSwitch HWICs:
• No more than two Ethernet Switch HWICs or network modules may be installed in a host router.
Multiple Ethernet Switch HWICs or network modules installed in a host router will not act independently of each other. They must be stacked, as they will not work at all otherwise.
• The ports of a Cisco EtherSwitch HWIC must NOT be connected to the Fast Ethernet/Gigabit onboard ports of the router.
• There is no inline power on the ninth port (port 8) of the HWIC-D-9ESW card.
• There is no Auto MDIX support on the ninth port (port 8) of the HWIC-D-9ESW card when either speed or duplex is not set to auto.
• There is no support for online insertion/removal (OIR) of the EtherSwitch HWICs.
• When Ethernet Switches have been installed and configured in a host router, OIR of the CompactFlash memory card in the router must not occur. OIR of the CompactFlash memory card will compromise the configuration of the Ethernet Switches.
• VTP pruning is not supported.
• There is a limit of 200 secure MAC addresses per module that can be supported by an EtherSwitch HWIC.
Prerequisites for Installing Two Ethernet Switch Network Modules in a Single Chassis
A maximum of two Ethernet switch network modules can be installed in a single chassis. If two Ethernet switch network modules of any type are installed in the same chassis, the following configuration requirements must be met:
• Both Ethernet switch network modules must have an optional Gigabit Ethernet expansion board installed.
• An Ethernet crossover cable must be connected to the two Ethernet switch network modules using the optional Gigabit Ethernet expansion board ports.
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• Intrachassis stacking for the optional Gigabit Ethernet expansion board ports must be configured. For information about intrachassis stacking configuration, see the 16- and 36-Port Ethernet Switch Module for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 series feature document.
Note Without this configuration and connection, duplications will occur in the VLAN databases, and unexpected packet handling may occur.
Information About EtherSwitch HWICsTo configure the Cisco HWIC-4ESW and HWIC-D-9ESW EtherSwitch HWICs, you should understand the following concepts:
• VLANs, page 85
• Inline Power for Cisco IP Phones, page 85
• Layer 2 Ethernet Switching, page 85
• 802.1x Authentication, page 86
• Spanning Tree Protocol, page 86
• Cisco Discovery Protocol, page 86
• Switched Port Analyzer, page 86
• IGMP Snooping, page 86
• Storm Control, page 86
• Intrachassis Stacking, page 86
• Fallback Bridging, page 87
VLANsFor information on the concept of VLANs, refer to the material at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_4/gt1636nm.htm#1047027
Inline Power for Cisco IP PhonesFor information on the concept of inline power for Cisco IP phones, refer to the material at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_4/gt1636nm.htm#1048439
Layer 2 Ethernet SwitchingFor information on the concept of Layer 2 Ethernet switching, refer to the material at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_4/gt1636nm.htm#1048478
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802.1x AuthenticationFor information on the concept of 802.1x authentication, refer to the material at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_4/gt1636nm.htm#1051006
Spanning Tree ProtocolFor information on the concept of Spanning Tree Protocol, refer to the material at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_4/gt1636nm.htm#1048458
Cisco Discovery ProtocolFor information on the concept of the Cisco Discovery Protocol, refer to the material at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_4/gt1636nm.htm#1048498
Switched Port AnalyzerFor information on the concept of switched port analyzer, refer to the material at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_4/gt1636nm.htm#1053663
IGMP SnoopingFor information on the concept of IGMP snooping, refer to the material at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_4/gt1636nm.htm#1053727
Storm ControlFor information on the concept of storm control, refer to the material at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_4/gt1636nm.htm#1051018
Intrachassis StackingFor information on the concept of intrachassis stacking, refer to the material at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_4/gt1636nm.htm#1051061
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Fallback BridgingFor information on the concept of fallback bridging, refer to the material at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_4/gt1636nm.htm#1054833
How to Configure EtherSwitch HWICsSee the following sections for configuration tasks for the EtherSwitch HWICs.
• Configuring VLANs, page 87
• Configuring VLAN Trunking Protocol, page 92
• Configuring Layer 2 Interfaces, page 95
• Configuring 802.1x Authentication, page 105
• Configuring Spanning Tree, page 117
• Configuring MAC Table Manipulation, page 127
• Configuring Cisco Discovery Protocol, page 131
• Configuring the Switched Port Analyzer (SPAN), page 135
• Configuring Power Management on the Interface, page 137
• Configuring IP Multicast Layer 3 Switching, page 139
• Configuring IGMP Snooping, page 143
• Configuring Per-Port Storm Control, page 149
• Configuring Stacking, page 152
• Configuring Fallback Bridging, page 154
• Configuring Separate Voice and Data Subnets, page 169
• Managing the EtherSwitch HWIC, page 172
Configuring VLANsThis section describes how to configure VLANs on the switch and contains the following sections:
• Adding a VLAN Instance, page 87
• Deleting a VLAN Instance from the Database, page 90
Adding a VLAN Instance
A total of 15 VLANs can be supported by an EtherSwitch HWIC.
Follow the steps below to configure a Fast Ethernet interface as Layer 2 access.
SUMMARY STEPS
1. enable
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2. vlan database
3. vlan vlan_id
4. exit
DETAILED STEPS
Verifying the VLAN Configuration
You can verify the VLAN configuration in VLAN database mode.
Use the show command in VLAN database mode to verify the VLAN configuration, as shown below:
Router(vlan)# show
VLAN ISL Id: 1 Name: default Media Type: Ethernet VLAN 802.10 Id: 100001 State: Operational MTU: 1500 Translational Bridged VLAN: 1002 Translational Bridged VLAN: 1003
VLAN ISL Id: 2 Name: VLAN0002 Media Type: Ethernet VLAN 802.10 Id: 100002 State: Operational MTU: 1500
VLAN ISL Id: 3 Name: Red_VLAN Media Type: Ethernet VLAN 802.10 Id: 100003 State: Operational MTU: 1500
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 vlan database
Example:Router# vlan database
Enters VLAN configuration mode.
Step 3 vlan vlan_id
Example:Router(vlan)# vlan 1
Adds an Ethernet VLAN.
Step 4 exit
Example:Router(vlan)# exit
Updates the VLAN database, propagates it throughout the administrative domain, and returns to privileged EXEC mode.
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VLAN ISL Id: 1002 Name: fddi-default Media Type: FDDI VLAN 802.10 Id: 101002 State: Operational MTU: 1500 Bridge Type: SRB Translational Bridged VLAN: 1 Translational Bridged VLAN: 1003
VLAN ISL Id: 1003 Name: token-ring-default Media Type: Token Ring VLAN 802.10 Id: 101003 State: Operational MTU: 1500 Bridge Type: SRB Ring Number: 0 Bridge Number: 1 Parent VLAN: 1005 Maximum ARE Hop Count: 7 Maximum STE Hop Count: 7 Backup CRF Mode: Disabled Translational Bridged VLAN: 1 Translational Bridged VLAN: 1002
VLAN ISL Id: 1004 Name: fddinet-default Media Type: FDDI Net VLAN 802.10 Id: 101004 State: Operational MTU: 1500 Bridge Type: SRB Bridge Number: 1 STP Type: IBM
VLAN ISL Id: 1005 Name: trnet-default Media Type: Token Ring Net VLAN 802.10 Id: 101005 State: Operational MTU: 1500 Bridge Type: SRB Bridge Number: 1 STP Type: IBM
Router(vlan)# exit
APPLY completed. Exiting.... Router# Router#
Enter the show vlan-switch command in EXEC mode using the Cisco IOS CLI to verify the VLAN configuration, as shown below.
Router# show vlan-switch
VLAN Name Status Ports ---- -------------------------------- --------- ---------------------------------- 1 default active Fa0/1/1, Fa0/1/2, Fa0/1/3, Fa0/1/4 Fa0/1/5, Fa0/1/6, Fa0/1/7, Fa0/1/8 Fa0/3/0, Fa0/3/2, Fa0/3/3, Fa0/3/4
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Fa0/3/5, Fa0/3/6, Fa0/3/7, Fa0/3/8 2 VLAN0002 active Fa0/1/0 3 Red_VLAN active 1002 fddi-default active 1003 token-ring-default active 1004 fddinet-default active 1005 trnet-default activeVLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2 ---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------ 1 enet 100001 1500 - - - - - 1002 1003 2 enet 100002 1500 - - - - - 0 0 3 enet 100003 1500 - - - - - 0 0 1002 fddi 101002 1500 - - - - - 1 1003 1003 tr 101003 1500 1005 0 - - srb 1 1002 1004 fdnet 101004 1500 - - 1 ibm - 0 0 1005 trnet 101005 1500 - - 1 ibm - 0 0
Router#
Deleting a VLAN Instance from the Database
You cannot delete the default VLANs for the different media types: Ethernet VLAN 1 and FDDI or Token Ring VLANs 1002 to 1005.
Follow the steps below to delete a VLAN from the database.
SUMMARY STEPS
1. enable
2. vlan database
3. no vlan vlan_id
4. exit
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DETAILED STEPS
Verifying VLAN Deletion
You can verify that a VLAN has been deleted from the switch in VLAN database mode.
Use the show command in VLAN database mode to verify that a VLAN has been deleted from the switch, as shown in the following output example:
Router(vlan)# show
VLAN ISL Id: 1 Name: default Media Type: Ethernet VLAN 802.10 Id: 100001 State: Operational MTU: 1500 Translational Bridged VLAN: 1002 Translational Bridged VLAN: 1003
VLAN ISL Id: 1002 Name: fddi-default Media Type: FDDI VLAN 802.10 Id: 101002 State: Operational MTU: 1500 Bridge Type: SRB Translational Bridged VLAN: 1 Translational Bridged VLAN: 1003<output truncated>
Router(vlan)#
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 vlan database
Example:Router# vlan database
Enters VLAN configuration mode.
Step 3 no vlan vlan_id
Example:Router(vlan)# no vlan 1
Deletes an Ethernet VLAN.
Step 4 exit
Example:Router(vlan)# exit
Updates the VLAN database, propagates it throughout the administrative domain, and returns to privileged EXEC mode.
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Enter the show vlan-switch brief command in EXEC mode, using the Cisco IOS CLI to verify that a VLAN has been deleted from the switch, as shown in the following output example:
Router# show vlan-switch brief
VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/1/0, Fa0/1/1, Fa0/1/2 Fa0/1/3, Fa0/1/4, Fa0/1/5 Fa0/1/6, Fa0/1/7, Fa0/1/8300 VLAN0300 active1002 fddi-default active1003 token-ring-default active1004 fddinet-default active1005 trnet-default activeRouter#
Configuring VLAN Trunking ProtocolThis section describes how to configure the VLAN Trunking Protocol (VTP) on an EtherSwitch HWIC, and contains the following tasks:
• Configuring a VTP Server, page 92
• Configuring a VTP Client, page 93
• Disabling VTP (VTP Transparent Mode), page 94
• Verifying VTP, page 95
Note VTP pruning is not supported by EtherSwitch HWICs.
Configuring a VTP Server
When a switch is in VTP server mode, you can change the VLAN configuration and have it propagate throughout the network.
Follow the steps below to configure the switch as a VTP server.
SUMMARY STEPS
1. enable
2. vlan database
3. vtp server
4. vtp domain domain_name
5. vtp password password_value
6. exit
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DETAILED STEPS
Configuring a VTP Client
When a switch is in VTP client mode, you cannot change the VLAN configuration on the switch. The client switch receives VTP updates from a VTP server in the management domain and modifies its configuration accordingly.
Follow the steps below to configure the switch as a VTP client.
SUMMARY STEPS
1. enable
2. vlan database
3. vtp client
4. exit
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 vlan database
Example:Router# vlan database
Enters VLAN configuration mode.
Step 3 vtp server
Example:Router(vlan)# vtp server
Configures the switch as a VTP server.
Step 4 vtp domain domain_name
Example:Router(vlan)# vtp domain distantusers
Defines the VTP domain name, which can be up to 32 characters long.
Step 5 vtp password password_value
Example:Router(vlan)# vtp password philadelphis
(Optional) Sets a password, which can be from 8 to 64 characters long, for the VTP domain.
Step 6 exit
Example:Router(vlan)# exit
Updates the VLAN database, propagates it throughout the administrative domain, exits VLAN configuration mode, and returns to privileged EXEC mode.
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DETAILED STEPS
Disabling VTP (VTP Transparent Mode)
When you configure the switch as VTP transparent, you disable VTP on the switch. A VTP transparent switch does not send VTP updates and does not act on VTP updates received from other switches.
Follow the steps below to disable VTP on the switch.
SUMMARY STEPS
1. enable
2. vlan database
3. vtp transparent
4. exit
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 vlan database
Example:Router# vlan database
Enters VLAN configuration mode.
Step 3 vtp client
Example:Router(vlan)# vtp client
Configures the switch as a VTP client.
Step 4 exit
Example:Router(vlan)# exit
Updates the VLAN database, propagates it throughout the administrative domain, exits VLAN configuration mode and returns to privileged EXEC mode.
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DETAILED STEPS
Verifying VTP
Use the show vtp status command to verify VTP status:
Router# show vtp status
VTP Version : 2Configuration Revision : 0Maximum VLANs supported locally : 256Number of existing VLANs : 5VTP Operating Mode : ServerVTP Domain Name : VTP Pruning Mode : DisabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0xBF 0x86 0x94 0x45 0xFC 0xDF 0xB5 0x70Configuration last modified by 0.0.0.0 at 0-0-00 00:00:00Local updater ID is 1.3.214.25 on interface Fa0/0 (first interface found)Router#
Configuring Layer 2 InterfacesThis section provides the following configuration information:
• Configuring a Range of Interfaces, page 96 (required)
• Defining a Range Macro, page 96 (optional)
• Configuring Layer 2 Optional Interface Features, page 97 (optional)
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 vlan database
Example:Router# vlan database
Enters VLAN configuration mode.
Step 3 vtp transparent
Example:Router(vlan)# vtp transparent
Configures VTP transparent mode.
Step 4 exit
Example:Router(vlan)# exit
Updates the VLAN database, propagates it throughout the administrative domain, exits VLAN configuration mode, and returns to privileged EXEC mode.
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Configuring a Range of Interfaces
Use the following task to configure a range of interfaces.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface range {macro macro_name | FastEthernet interface-id [ - interface-id] | vlan vlan_ID} [, FastEthernet interface-id [ - interface-id] | vlan vlan-ID]
DETAILED STEPS
Defining a Range Macro
Use the following task to define an interface range macro.
SUMMARY STEPS
1. enable
2. configure terminal
3. define interface-range macro_name {FastEthernet interface-id [ - interface-id] | {vlan vlan_ID - vlan_ID} | [, FastEthernet interface-id [ - interface-id]
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface range {macro macro_name | FastEthernet interface-id [ - interface-id] | vlan vlan-ID} [, FastEthernet interface-id [ - interface-id] | vlan vlan-ID]
Example:Router(config)# interface range FastEthernet 0/1/0 - 0/1/3
Select the range of interfaces to be configured.
• The space before the dash is required. For example, the command interface range fastethernet 0/<slot>/0 - 0/<slot>/3 is valid; the command interface range fastethernet 0/<slot>/0-0/<slot>/3 is not valid.
• You can enter one macro or up to five comma-separated ranges.
• Comma-separated ranges can include both VLANs and physical interfaces.
• You are not required to enter spaces before or after the comma.
• The interface range command only supports VLAN interfaces that are configured with the interface vlan command.
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DETAILED STEPS
Verifying Configuration of an Interface Range Macro
Use the show running-configuration command to show the defined interface-range macro configuration, as shown below:
Router# show running-configuration | include define
define interface-range first_three FastEthernet0/1/0 - 2
Configuring Layer 2 Optional Interface Features
• Interface Speed and Duplex Configuration Guidelines, page 97
• Configuring the Interface Speed, page 98
• Configuring the Interface Duplex Mode, page 98
• Verifying Interface Speed and Duplex Mode Configuration, page 99
• Configuring a Description for an Interface, page 100
• Configuring a Fast Ethernet Interface as a Layer 2 Trunk, page 101
• Configuring a Fast Ethernet Interface as Layer 2 Access, page 103
Interface Speed and Duplex Configuration Guidelines
When configuring an interface speed and duplex mode, note these guidelines:
• If both ends of the line support autonegotiation, Cisco highly recommends the default auto negotiation settings.
• If one interface supports auto negotiation and the other end does not, configure duplex and speed on both interfaces; do not use the auto setting on the supported side.
• Both ends of the line need to be configured to the same setting; for example, both hard-set or both auto-negotiate. Mismatched settings are not supported.
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 define interface-range macro_name {FastEthernet interface-id [ - interface-id] | {vlan vlan_ID - vlan-ID} | [, FastEthernet interface-id [ - interface-id]
Example:Router(config)# define interface-range first_three FastEthernet0/1/0 - 2
• Defines a range of macros.
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Caution Changing the interface speed and duplex mode configuration might shut down and reenable the interface during the reconfiguration.
Configuring the Interface Speed
Use the following task to set the interface speed.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface fastethernet interface-id
4. speed [10 | 100 | auto]
DETAILED STEPS
Note If you set the interface speed to auto on a 10/100-Mbps Ethernet interface, both speed and duplex are automatically negotiated.
Configuring the Interface Duplex Mode
Follow the steps below to set the duplex mode of a Fast Ethernet interface.
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface fastethernet interface-id
Example:Router(config)# interface fastethernet 0/1/0
Selects the interface to be configured.
Step 4 speed [10 | 100 | auto ]
Example:Router(config-if)# speed 100
Selects the interface to be configured.
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SUMMARY STEPS
1. enable
2. configure terminal
3. interface fastethernet interface-id
4. duplex [auto | full | half]
DETAILED STEPS
Note If you set the port speed to auto on a 10/100-Mbps Ethernet interface, both speed and duplex are automatically negotiated. You cannot change the duplex mode of auto negotiation interfaces.
The following example shows how to set the interface duplex mode to auto on Fast Ethernet interface 3:
Router(config)# interface fastethernet 0/1/0Router(config-if)# speed 100Router(config-if)# duplex autoRouter(config-if)# end
Verifying Interface Speed and Duplex Mode Configuration
Use the show interfaces command to verify the interface speed and duplex mode configuration for an interface, as shown in the following output example.
Router# show interfaces fastethernet 0/1/0
FastEthernet0/1/0 is up, line protocol is upHardware is Fast Ethernet, address is 000f.f70a.f272 (bia 000f.f70a.f272)MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255Encapsulation ARPA, loopback not setKeepalive set (10 sec)
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface fastethernet interface-id
Example:Router(config)# interface fastethernet 0/1/0
Selects the interface to be configured.
Step 4 duplex [auto | full | half]
Example:Router(config-if)# duplex auto
Sets the duplex mode of the interface.
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Auto-duplex, Auto-speedARP type: ARPA, ARP Timeout 04:00:00Last input 00:00:11, output never, output hang neverLast clearing of "show interface" counters neverQueueing strategy: fifoOutput queue 0/40, (size/max)5 minute input rate 0 bits/sec, 0 packets/sec5 minute output rate 0 bits/sec, 0 packets/sec 4 packets input, 1073 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 input packets with dribble condition detected 6 packets output, 664 bytes, 0 underruns(0/0/0) 0 output errors, 0 collisions, 3 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out
Router#
Configuring a Description for an Interface
You can add a description of an interface to help you remember its function. The description appears in the output of the following commands: show configuration, show running-config, and show interfaces.
Use the description command to add a description for an interface.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface fastethernet interface-id
4. description string
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DETAILED STEPS
Configuring a Fast Ethernet Interface as a Layer 2 Trunk
Use this task to configure a Fast Ethernet interface as a Layer 2 trunk.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface fastethernet interface-id
4. shutdown
5. switchport mode trunk
6. switchport trunk native vlan vlan-num
7. switchport trunk allowed vlan {add | except | none | remove} vlan1[,vlan[,vlan[,...]]
8. no shutdown
9. end
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface fastethernet interface-id
Example:Router(config)# interface fastethernet 0/1/0
Selects the interface to be configured.
Step 4 description string
Example:Router(config-if)# description newinterface
Adds a description for an interface.
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DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface fastethernet interface-id
Example:Router(config)# interface fastethernet 0/1/0
Selects the interface to be configured.
Step 4 shutdown
Example:
Router(config-if)# shutdown
(Optional) Shuts down the interface to prevent traffic flow until configuration is complete.
Step 5 switchport mode trunk
Example:Router(config-if)# switchport mode trunk
Configures the interface as a Layer 2 trunk.
Note Encapsulation is always dot1q.
Step 6 switchport trunk native vlan vlan-num
Example:Router(config-if)# switchport trunk native vlan 1
(Optional) For 802.1Q trunks, specifies the native VLAN.
Step 7 switchport trunk allowed vlan {add | except | none | remove} vlan1[,vlan[,vlan[,...]]
Example:Router(config-if)# switchport trunk allowed vlan add vlan1, vlan2, vlan3
(Optional) Configures the list of VLANs allowed on the trunk. All VLANs are allowed by default. You cannot remove any of the default VLANs from a trunk.
Step 8 no shutdown
Example:Router(config-if)# no shutdown
Activates the interface. (Required only if you shut down the interface.)
Step 9 end
Example:Router(config-if)# end
Exits configuration mode.
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Note Ports do not support Dynamic Trunk Protocol (DTP). Ensure that the neighboring switch is set to a mode that will not send DTP.
Verifying a Fast Ethernet Interface as a Layer 2 Trunk
Use the following show commands to verify the configuration of a Fast Ethernet interface as a Layer 2 trunk.
router# show running-config interfaces fastEthernet 0/3/1
Building configuration...Current configuration: 71 bytes ! interface FastEthernet0/3/1 switchport mode trunk no ip address endRouter#
Router# show interfaces trunk
Port Mode Encapsulation Status Native vlan Fa0/3/1 on 802.1q trunking 1
Port Vlans allowed on trunk Fa0/3/1 1-1005
Port Vlans allowed and active in management domain Fa0/3/1 1
Port Vlans in spanning tree forwarding state and not pruned Fa0/3/1 1
Router#
Configuring a Fast Ethernet Interface as Layer 2 Access
Follow these steps below to configure a Fast Ethernet interface as Layer 2 access.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface fastethernet interface-id
4. shutdown
5. switchport mode access
6. switchport access vlan vlan-num
7. no shutdown
8. end
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DETAILED STEPS
Verifying a Fast Ethernet Interface as Layer 2 Access
Use the show running-config interface command to verify the running configuration of the interface, as shown below.
Router# show running-config interface fastethernet 0/1/2
Building configuration...Current configuration: 76 bytes ! interface FastEthernet0/1/2
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface fastethernet interface-id
Example:Router(config)# interface fastethernet 0/1/0
Selects the interface to be configured.
Step 4 shutdown
Example:
Router(config-if)# shutdown
(Optional) Shuts down the interface to prevent traffic flow until configuration is complete.
Step 5 switchport mode access
Example:Router(config-if)# switchport mode access
Configures the interface as a Layer 2 access.
Step 6 switchport access vlan vlan-num
Example:Router(config-if)# switchport access vlan 1
For access ports, specifies the access VLAN.
Step 7 no shutdown
Example:Router(config-if)# no shutdown
Activates the interface.
• Required only if you shut down the interface.
Step 8 end
Example:Router(config-if)# end
Exits configuration mode.
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switchport access vlan 3 no ip address end
Use the show interfaces command to verify the switchport configuration of the interface, as shown below.
Router# show interfaces f0/1/0 switchport
Name: Fa0/1/0Switchport: EnabledAdministrative Mode: static accessOperational Mode: static accessAdministrative Trunking Encapsulation: dot1qOperational Trunking Encapsulation: nativeNegotiation of Trunking: DisabledAccess Mode VLAN: 1 (default)Trunking Native Mode VLAN: 1 (default)Trunking VLANs Enabled: ALLTrunking VLANs Active: 1Priority for untagged frames: 0Override vlan tag priority: FALSEVoice VLAN: noneAppliance trust: none
Router#
Configuring 802.1x AuthenticationThis section describes how to configure 802.1x port-based authentication on an EtherSwitch HWIC:
• Information About the Default 802.1x Configuration, page 105
• Enabling 802.1x Authentication, page 107
• Configuring the Switch-to-RADIUS-Server Communication, page 108
• Enabling Periodic Reauthentication, page 110
• Changing the Quiet Period, page 111
• Changing the Switch-to-Client Retransmission Time, page 112
• Setting the Switch-to-Client Frame-Retransmission Number, page 114
• Enabling Multiple Hosts, page 115
• Resetting the 802.1x Configuration to the Default Values, page 116
• Displaying 802.1x Statistics and Status, page 117
Information About the Default 802.1x Configuration
Table 8 shows the default 802.1x configuration.
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802.1x Configuration Guidelines
These are the 802.1x authentication configuration guidelines:
• When the 802.1x protocol is enabled, ports are authenticated before any other Layer 2 feature is enabled.
• The 802.1x protocol is supported on Layer 2 static-access ports, but it is not supported on these port types:
– Trunk port—If you try to enable 802.1x on a trunk port, an error message appears, and 802.1x is not enabled. If you try to change the mode of an 802.1x-enabled port to trunk, the port mode is not changed.
Table 8 Default 802.1x Configuration
Feature Default Setting
Authentication, authorization, and accounting (AAA)
Disabled.
RADIUS server
• IP address
• UDP authentication port
• Key
• None specified.
• 1645.
• None specified.
Per-interface 802.1x enable state Disabled (force-authorized).
The port transmits and receives normal traffic without 802.1x-based authentication of the client.
Periodic reauthentication Disabled.
Number of seconds between reauthentication attempts
3600 seconds.
Quiet period 60 seconds (number of seconds that the switch remains in the quiet state following a failed authentication exchange with the client).
Retransmission time 30 seconds (number of seconds that the switch should wait for a response to an EAP request/identity frame from the client before retransmitting the request).
Maximum retransmission number 2 times (number of times that the switch will send an EAP-request/identity frame before restarting the authentication process).
Multiple host support Disabled.
Client timeout period 30 seconds (when relaying a request from the authentication server to the client, the amount of time the switch waits for a response before retransmitting the request to the client). This setting is not configurable.
Authentication server timeout period 30 seconds (when relaying a response from the client to the authentication server, the amount of time the switch waits for a reply before retransmitting the response to the server). This setting is not configurable.
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– Switch Port Analyzer (SPAN) destination port—You can enable 802.1x on a port that is a SPAN destination port; however, 802.1x is disabled until the port is removed as a SPAN destination. You can enable 802.1x on a SPAN source port.
Enabling 802.1x Authentication
To enable 802.1x port-based authentication, you must enable AAA and specify the authentication method list. A method list describes the sequence and authentication methods to be queried to authenticate a user.
The software uses the first method listed to authenticate users; if that method fails to respond, the software selects the next authentication method in the method list. This process continues until there is successful communication with a listed authentication method or until all defined methods are exhausted. If authentication fails at any point in this cycle, the authentication process stops, and no other authentication methods are attempted.
Beginning in privileged EXEC mode, follow these steps to configure 802.1x port-based authentication. This procedure is required.
SUMMARY STEPS
1. enable
2. configure terminal
3. aaa authentication dot1x {default | listname} method1 [method2...]
4. interface interface-id
5. dot1x port-control auto
6. end
7. show dot1x
8. copy running-config startup-config
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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To disable AAA, use the no aaa new-model global configuration command. To disable 802.1x AAA authentication, use the no aaa authentication dot1x {default | list-name} method1 [method2...] global configuration command. To disable 802.1x, use the dot1x port-control force-authorized or the no dot1x port-control interface configuration command.
Configuring the Switch-to-RADIUS-Server Communication
RADIUS security servers are identified by their host name or IP address, host name and specific UDP port numbers, or IP address and specific UDP port numbers. The combination of the IP address and UDP port number creates a unique identifier, which enables RADIUS requests to be sent to multiple UDP ports on a server at the same IP address. If two different host entries on the same RADIUS server are
Step 3 aaa authentication dot1x {default | listname} method1 [method2...]
Example:
Router(config)# aaa authentication dot1x default newmethod
Creates an 802.1x authentication method list.
• To create a default list that is used when a named list is not specified in the authentication command, use the default keyword followed by the methods that are to be used in default situations. The default method list is automatically applied to all interfaces.
• Enter at least one of these keywords:
– group radius—Use the list of all RADIUS servers for authentication.
– none—Use no authentication. The client is automatically authenticated without the switch using the information supplied by the client.
Step 4 interface interface-id
Example:Router(config)# interface 0/1/3
Enters interface configuration mode and specifies the interface to be enabled for 802.1x authentication.
Step 5 dot1x port-control auto
Example:Router(config-if)# dot1x port-control auto
Enables 802.1x on the interface.
• For feature interaction information with trunk, dynamic, dynamic-access, EtherChannel, secure, and SPAN ports see the “802.1x Configuration Guidelines” section on page 106.
Step 6 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 7 show dot1x
Example:Router# show dot1x
Verifies your entries.
Step 8 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entries in the configuration file.
Command or Action Purpose
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configured for the same service—for example, authentication—the second host entry configured acts as the fail-over backup to the first one. The RADIUS host entries are tried in the order that they were configured.
Follow these steps to configure the RADIUS server parameters on the switch. This procedure is required.
SUMMARY STEPS
1. enable
2. configure terminal
3. radius-server host {hostname | ip-address} auth-port port-number key string
4. end
5. show running-config
6. copy running-config startup-config
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 radius-server host {hostname | ip-address} auth-port port-number key string
Example:Router# raduis-server host hostseven auth-port 75 key newauthority75
Configures the RADIUS server parameters on the switch.
• For hostname | ip-address, specify the host name or IP address of the remote RADIUS server.
• For auth-port port-number, specify the UDP destination port for authentication requests. The default is 1645.
• For key string, specify the authentication and encryption key used between the switch and the RADIUS daemon running on the RADIUS server. The key is a text string that must match the encryption key used on the RADIUS server.
NoteAlways configure the key as the last item in the radius-server host command syntax because leading spaces are ignored, but spaces within and at the end of the key are used. If you use spaces in the key, do not enclose the key in quotation marks unless the quotation marks are part of the key. This key must match the encryption used on the RADIUS daemon.
• If you want to use multiple RADIUS servers, repeat this command.
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To delete the specified RADIUS server, use the no radius-server host {hostname | ip-address} global configuration command.
You can globally configure the timeout, retransmission, and encryption key values for all RADIUS servers by using the radius-server host global configuration command. If you want to configure these options on a per-server basis, use the radius-server timeout, radius-server retransmit, and the radius-server key global configuration commands.
You also need to configure some settings on the RADIUS server. These settings include the IP address of the switch and the key string to be shared by both the server and the switch. For more information, refer to the RADIUS server documentation.
Enabling Periodic Reauthentication
You can enable periodic 802.1x client reauthentication and specify how often it occurs. If you do not specify a time period before enabling reauthentication, the number of seconds between reauthentication attempts is 3600 seconds.
Automatic 802.1x client reauthentication is a global setting and cannot be set for clients connected to individual ports.
Follow these steps to enable periodic reauthentication of the client and to configure the number of seconds between reauthentication attempts.
SUMMARY STEPS
1. enable
2. configure terminal
3. dot1x re-authentication
4. dot1x timeout re-authperiod seconds
5. end
6. show dot1x
7. copy running-config startup-config
Step 4 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 5 show running-config
Example:Router# show running-config
Verifies your entries.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entries in the configuration file.
Command or Action Purpose
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DETAILED STEPS
To disable periodic reauthentication, use the no dot1x re-authentication global configuration command. To return to the default number of seconds between reauthentication attempts, use the no dot1x timeout re-authperiod global configuration command.
Changing the Quiet Period
When the switch cannot authenticate the client, the switch remains idle for a set period of time, and then tries again. The idle time is determined by the quiet-period value. A failed authentication of the client might occur because the client provided an invalid password. You can provide a faster response time to the user by entering smaller number than the default.
Follow these steps to change the quiet period.
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 dot1x re-authentication
Example:Router(config)# dot1x re-authentication
Enables periodic reauthentication of the client.
• Periodic reauthentication is disabled by default.
Step 4 dot1x timeout re-authperiod seconds
Example:
Router(config)# dot1x timeout re-authperiod 120
Sets the number of seconds between reauthentication attempts.
• The range is 1 to 4294967295; the default is 3600 seconds.
• This command affects the behavior of the switch only if periodic reauthentication is enabled
Step 5 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 6 show dot1x
Example:Router# show dot1x
Verifies your entries.
Step 7 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entries in the configuration file.
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SUMMARY STEPS
1. enable
2. configure terminal
3. dot1x timeout quiet-period seconds
4. end
5. show dot1x
6. copy running-config startup-config
DETAILED STEPS
To return to the default quiet time, use the no dot1x timeout quiet-period global configuration command.
Changing the Switch-to-Client Retransmission Time
The client responds to the EAP-request/identity frame from the switch with an EAP-response/identity frame. If the switch does not receive this response, it waits a set period of time (known as the retransmission time), and then retransmits the frame.
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 dot1x timeout quiet-period seconds
Example:Router(config)#dot1x timeout quiet-period 120
Sets the number of seconds that the switch remains in the quiet state following a failed authentication exchange with the client.
• The range is 0 to 65535 seconds; the default is 60.
Step 4 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 5 show dot1x
Example:Router# show dot1x
Verifies your entries.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entries in the configuration file.
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Note You should change the default value of this command only to adjust for unusual circumstances such as unreliable links or specific behavioral problems with certain clients and authentication servers.
Follow the steps below to change the amount of time that the switch waits for client notification.
SUMMARY STEPS
1. enable
2. configure terminal
3. dot1x timeout tx-period seconds
4. end
5. show dot1x
6. copy running-config startup-config
DETAILED STEPS
To return to the default retransmission time, use the no dot1x timeout tx-period global configuration command.
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 dot1x timeout tx-period seconds
Example:Router(config)# dot1x timeout tx-period seconds
Sets the number of seconds that the switch waits for a response to an EAP-request/identity frame from the client before retransmitting the request.
• The range is 1 to 65535 seconds; the default is 30.
Step 4 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 5 show dot1x
Example:Router# show dot1x
Verifies your entries.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entries in the configuration file.
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Setting the Switch-to-Client Frame-Retransmission Number
In addition to changing the switch-to-client retransmission time, you can change the number of times that the switch sends an EAP-request/identity frame (assuming no response is received) to the client before restarting the authentication process.
Note You should change the default value of this command only to adjust for unusual circumstances such as unreliable links or specific behavioral problems with certain clients and authentication servers.
Follow the steps below to set the switch-to-client frame-retransmission number.
SUMMARY STEPS
1. enable
2. configure terminal
3. dot1x max-req count
4. end
5. show dot1x
6. copy running-config startup-config
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 dot1x max-req count
Example:Router(config)# dot1x max-req 5
Sets the number of times that the switch sends an EAP-request/identity frame to the client before restarting the authentication process.
• The range is 1 to 10; the default is 2.
Step 4 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
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To return to the default retransmission number, use the no dot1x max-req global configuration command.
Enabling Multiple Hosts
You can attach multiple hosts to a single 802.1x-enabled port. In this mode, only one of the attached hosts must be successfully authorized for all hosts to be granted network access. If the port becomes unauthorized (reauthentication fails, and an EAPOL-logoff message is received), all attached clients are denied access to the network.
Follow these steps below to allow multiple hosts (clients) on an 802.1x-authorized port that has the dot1x port-control interface configuration command set to auto.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface interface-id
4. dot1x multiple-hosts
5. end
6. show dot1x interface interface-id
7. copy running-config startup-config
DETAILED STEPS
Step 5 show dot1x
Example:Router# show dot1x
Verifies your entries.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entries in the configuration file.
Command or Action Purpose
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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To disable multiple hosts on the port, use the no dot1x multiple-hosts interface configuration command.
Resetting the 802.1x Configuration to the Default Values
You can reset the 802.1x configuration to the default values with a single command.
Follow these steps to reset the 802.1x configuration to the default values.
SUMMARY STEPS
1. enable
2. configure terminal
3. dot1x default
4. end
5. show dot1x
6. copy running-config startup-config
Step 3 interface interface-id
Example:Router# interface 0/1/2
Enters interface configuration mode.
Step 4 dot1x multiple-hosts
Example:Router(config-if)# dot1x multiple-hosts
Allows multiple hosts (clients) on an 802.1x-authorized port.
• Make sure that the dot1x port-control interface configuration command is set to auto for the specified interface.
Step 5 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 6 show dot1x
Example:Router# show dot1x
Verifies your entries.
Step 7 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entries in the configuration file.
Command or Action Purpose
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DETAILED STEPS
Displaying 802.1x Statistics and Status
To display 802.1x statistics for all interfaces, use the show dot1x statistics privileged EXEC command. To display 802.1x statistics for a specific interface, use the show dot1x statistics interface interface-id privileged EXEC command.
To display the 802.1x administrative and operational status for the switch, use the show dot1x privileged EXEC command. To display the 802.1x administrative and operational status for a specific interface, use the show dot1x interface interface-id privileged EXEC command.
Configuring Spanning Tree• Enabling Spanning Tree, page 118
• Configuring Spanning Tree Port Priority, page 119
• Configuring Spanning Tree Port Cost, page 120
• Configuring the Bridge Priority of a VLAN, page 123
• Configuring Hello Time, page 124
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 dot1x default
Example:Router(config)# dot1x default
Resets the configurable 802.1x parameters to the default values.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show dot1x
Example:Router# show dot1x
Verifies your entries.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entries in the configuration file.
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• Configuring the Forward-Delay Time for a VLAN, page 124
• Configuring the Maximum Aging Time for a VLAN, page 125
• Configuring the Root Bridge, page 126
Enabling Spanning Tree
You can enable spanning tree on a per-VLAN basis. The switch maintains a separate instance of spanning tree for each VLAN (except on VLANs on which you disable spanning tree).
SUMMARY STEPS
1. enable
2. configure terminal
3. spanning-tree vlan vlan-ID
4. end
5. show spanning-tree vlan vlan-id
DETAILED STEPS
Example
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 spanning-tree vlan vlan-ID
Example:Router(config)# spanning-tree vlan 200
Enables spanning tree on a per-VLAN basis
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show spanning-tree vlan vlan-id
Example:Router# show spanning-tree vlan 200
Verifies spanning tree configuration
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Use the show spanning-tree vlan to verify spanning tree configuration, as illustrated below:
Router# show spanning-tree vlan 200
VLAN200 is executing the ieee compatible Spanning Tree protocol Bridge Identifier has priority 32768, address 0050.3e8d.6401 Configured hello time 2, max age 20, forward delay 15 Current root has priority 16384, address 0060.704c.7000 Root port is 264 (FastEthernet0/1/8), cost of root path is 38 Topology change flag not set, detected flag not set Number of topology changes 0 last change occurred 01:53:48 ago Times: hold 1, topology change 24, notification 2 hello 2, max age 14, forward delay 10 Timers: hello 0, topology change 0, notification 0
Port 264 (FastEthernet0/1/8) of VLAN200 is forwarding Port path cost 19, Port priority 128, Port Identifier 129.9. Designated root has priority 16384, address 0060.704c.7000 Designated bridge has priority 32768, address 00e0.4fac.b000 Designated port id is 128.2, designated path cost 19 Timers: message age 3, forward delay 0, hold 0 Number of transitions to forwarding state: 1 BPDU: sent 3, received 3417 Router#
Configuring Spanning Tree Port Priority
Follow the steps below to configure the spanning tree port priority of an interface.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet} interface-id
4. spanning-tree port-priority port-priority
5. spanning-tree vlan vlan-ID port-priority port-priority
6. end
7. show spanning-tree interface
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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Example
Use the show spanning-tree interface to verify spanning-tree interface and the spanning-tree port priority configuration, as illustrated below:
Router# show spanning-tree interface fastethernet 0/1/6
Port 264 (FastEthernet0/1/6) of VLAN200 is forwarding Port path cost 19, Port priority 100, Port Identifier 129.8. Designated root has priority 32768, address 0010.0d40.34c7 Designated bridge has priority 32768, address 0010.0d40.34c7 Designated port id is 128.1, designated path cost 0 Timers: message age 2, forward delay 0, hold 0 Number of transitions to forwarding state: 1 BPDU: sent 0, received 13513Router#
Configuring Spanning Tree Port Cost
Spanning tree port costs are explained in the following section.
Step 3 interface {ethernet | fastethernet} interface-id
Example:Router(config)# interface fastethernet 0/1/6
Selects an interface to configure.
Step 4 spanning-tree port-priority port-priority
Example:Router(config-if)# spanning-tree port-priority 8
Configures the port priority for an interface.
• The of port-priority value can be from 4 to 252 in increments of 4.
• Use the no form of this command to restore the defaults.
Step 5 spanning-tree vlan vlan-ID port-priority port-priority
Example:Router (config-if)# spanning-tree vlan vlan1 port-priority 12
Configures the priority for a VLAN.
Step 6 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 7 show spanning-tree interface fastethernet interface-id
Example:Router# show spanning-tree interface fastethernet 0/1/6
(Optional) Saves your entries in the configuration file.
Command or Action Purpose
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Calculating Port Cost
Port cost value calculations are based on the bandwidth of the port. There are two classes of values. Short (16-bit) values are specified by the IEEE 802.1D specification and range in value from 1 to 65535. Long (32-bit) values are specified by the IEEE 802.1t specification and range in value from 1 to 200,000,000.
Assigning Short Port Cost Values
You can manually assign port costs in the range of 1 to 65535. Default cost values are as follows.
Assigning Long Port Cost Values
You can manually assign port costs in the range of 1 to 200,000,000. Recommended cost values are as follows.
Follow the steps below to configure the spanning tree port cost of an interface.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet} interface-id
4. spanning-tree cost port-cost
5. spanning-tree vlan vlan-ID cost port-cost
6. end
7. show spanning-tree interface
Port Speed Default Cost Value
10 Mbps 100
100 Mbps 19
Port Speed Recommended Value Recommended Range
10 Mbps 2,000,000 200,000 to 20,000,000
100 Mbps 200,000 20,000 to 2,000,000
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DETAILED STEPS
Example
Use the show spanning-tree vlan to verify the spanning-tree port cost configuration.
Router# show spanning-tree vlan 200
Port 264 (FastEthernet0/1/8) of VLAN200 is forwardingPort path cost 17, Port priority 64, Port Identifier 129.8. Designated root has priority 32768, address 0010.0d40.34c7 Designated bridge has priority 32768, address 0010.0d40.34c7 Designated port id is 128.1, designated path cost 0 Timers: message age 2, forward delay 0, hold 0
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface {ethernet | fastethernet} interface-id
Example:Router(config)# interface fastethernet 0/1/6
Selects an interface to configure.
Step 4 spanning-tree cost port-cost
Example:Router(config-if)# spanning-tree cost 2000
Configures the port cost for an interface.
• The value of port_cost can be from 1 to 200,000,000 (1 to 65,535 in Cisco IOS Releases 12.1(2)E and earlier).
• Use the no form of this command to restore the defaults.
Step 5 spanning-tree vlan vlan-ID cost port-cost
Example:Router(config-if)# spanning-tree vlan 200 cost 2000
Configures the VLAN port cost for an interface.
• The value port-cost can be from 1 to 65,535.
• Use the no form of this command to restore the defaults.
Step 6 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 7 show spanning-tree interface fastethernet interface-id
Example:Router# show spanning-tree interface fastethernet 0/1/6
(Optional) Saves your entries in the configuration file.
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Number of transitions to forwarding state: 1 BPDU: sent 0, received 13513
Router#
Configuring the Bridge Priority of a VLAN
Use the following task to configure the spanning tree bridge priority of a VLAN.
SUMMARY STEPS
1. enable
2. configure terminal
3. spanning-tree vlan vlan-ID priority bridge-priority
4. show spanning-tree vlan bridge [brief]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 spanning-tree vlan vlan-ID priority bridge-priority
Example:Router(config)# spanning-tree vlan 200 priority 2
Configures the bridge priority of a VLAN. The bridge_priority value can be from 1 to 65535.
• Use the no form of this command to restore the defaults.
Caution Exercise care when using this command. For most situations spanning-tree vlan vlan-ID root primary and the spanning-tree vlan vlan-ID root secondary are the preferred commands to modify the bridge priority.
Step 4 show spanning-tree vlan bridge
Example:Router(config-if)# spanning-tree cost 200
Verifies the bridge priority.
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Example
Use the show spanning-tree vlan bridge command to verify the bridge priority, as shown below.
Router# show spanning-tree vlan 200 bridge brief
Hello Max FwdVlan Bridge ID Time Age Delay Protocol---------------- -------------------- ---- ---- ----- --------VLAN200 33792 0050.3e8d.64c8 2 20 15 ieeeRouter#
Configuring Hello Time
Use the following tasks to configure the hello interval for the spanning tree.
SUMMARY STEPS
1. enable
2. configure terminal
3. spanning-tree vlan vlan-ID hello-time hello-time
DETAILED STEPS
Configuring the Forward-Delay Time for a VLAN
Use the following task to configure the forward delay for the spanning tree
SUMMARY STEPS
1. enable
2. configure terminal
3. spanning-tree vlan vlan-ID forward-time forward-time
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 spanning-tree vlan vlan-ID hello-time hello-time
Example:Router(config)# spanning-tree vlan 200 hello-time 5
Configures the hello time of a VLAN.
• The hello_time value can be from 1 to 10 seconds.
• Use the no form of this command to restore the defaults
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DETAILED STEPS
Configuring the Maximum Aging Time for a VLAN
Follow the steps below to configure the maximum age interval for the spanning tree.
SUMMARY STEPS
1. enable
2. configure terminal
3. spanning-tree vlan vlan-ID max-age max-age
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 spanning-tree vlan vlan-ID forward-time forward-time
Example:Router(config)# spanning-tree vlan 20 forward-time 5
Configures the forward time of a VLAN.
• The value of forward-time can be from 4 to 30 seconds.
• Use the no form of this command to restore the defaults.
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 spanning-tree vlan vlan-ID max-age max-age
Example:Router(config)# spanning-tree vlan 200 max-age 30
Configures the maximum aging time of a VLAN.
• The value of max_age can be from 6 to 40 seconds.
• Use the no form of this command to restore the defaults.
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Configuring the Root Bridge
The EtherSwitch HWIC maintains a separate instance of spanning tree for each active VLAN configured on the switch. A bridge ID, consisting of the bridge priority and the bridge MAC address, is associated with each instance. For each VLAN, the switch with the lowest bridge ID will become the root bridge for that VLAN.
To configure a VLAN instance to become the root bridge, the bridge priority can be modified from the default value (32768) to a significantly lower value so that the bridge becomes the root bridge for the specified VLAN. Use the spanning-tree vlan root command to alter the bridge priority.
The switch checks the bridge priority of the current root bridges for each VLAN. The bridge priority for the specified VLANs is set to 8192 if this value will cause the switch to become the root for the specified VLANs.
If any root switch for the specified VLANs has a bridge priority lower than 8192, the switch sets the bridge priority for the specified VLANs to 1 less than the lowest bridge priority.
For example, if all switches in the network have the bridge priority for VLAN 100 set to the default value of 32768, entering the spanning-tree vlan 100 root primary command on a switch will set the bridge priority for VLAN 100 to 8192, causing the switch to become the root bridge for VLAN 100.
Note The root switch for each instance of spanning tree should be a backbone or distribution switch. Do not configure an access switch as the spanning tree primary root.
Use the diameter keyword to specify the Layer 2 network diameter (that is, the maximum number of bridge hops between any two end stations in the Layer 2 network). When you specify the network diameter, the switch automatically picks an optimal hello time, forward delay time, and maximum age time for a network of that diameter, which can significantly reduce the spanning tree convergence time. You can use the hello keyword to override the automatically calculated hello time.
Note We recommend that you avoid configuring the hello time, forward delay time, and maximum age time manually after configuring the switch as the root bridge.
Follow these steps to configure the switch as the root.:
SUMMARY STEPS
1. enable
2. configure terminal
3. spanning-tree vlan vlaN-ID root primary [diameter hops [hello-time seconds]]
4. end
5. no spanning-tree vlan vlan-ID
6. show spanning-tree vlan vlan-ID
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DETAILED STEPS
Example
Use the show spanning-tree vlan command to verify the that the spanning tree is disabled, as illustrated below:
Router# show spanning-tree vlan 200
<output truncated>Spanning tree instance for VLAN 200 does not exist.Router#
Configuring MAC Table ManipulationPort security is implemented by providing the user with the option to make a port secure by allowing only well-known MAC addresses to send in data traffic. Up to 200 secure MAC addresses per HWIC are supported.
• Enabling Known MAC Address Traffic, page 128
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 spanning-tree vlan vlan-ID root primary [diameter hops [hello-time seconds]]
Example:Router(config)# spanning-tree vlan 200 root primary
Configures a switch as the root switch.
• Use the no form of this command to restore the defaults.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 no spanning-tree vlan vlan-ID
Example:Router(config)# spanning-tree vlan 200 root primary
Disables spanning tree on a per-VLAN basis.
Step 6 show spanning-tree vlan vlan-ID
Example:Router(config)# show spanning-tree vlan 200
Verifies spanning tree on a per-VLAN basis.
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• Creating a Static Entry in the MAC Address Table, page 129
• Configuring and Verifying the Aging Timer, page 130
Enabling Known MAC Address Traffic
Follow these steps to enable the MAC address secure option.
SUMMARY STEPS
1. enable
2. configure terminal
3. mac-address-table secure mac-address fastethernet interface-id [vlan vlan-id]
4. end
5. show mac-address-table secure
DETAILED STEPS
Example
Use the show mac-address-table secure to verify the configuration, as illustrated below:
Router# show mac-address-table secure
Secure Address Table:
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 mac-address-table secure mac-address fastethernet interface-id [vlan vlan-id]]
Example:Router(config)# mac-address-table secure 0000.0002.0001 fastethernet 0/1/1 vlan 2
Secures the MAC address traffic on the port.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show mac-address-table secure
Example:Router# show mac-address-table secure
Verifies the configuration.
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Destination Address Address Type VLAN Destination Port------------------- ------------ ---- --------------------0000.0002.0001 Secure 2 FastEthernet0/1/1
Creating a Static Entry in the MAC Address Table
Follow these steps to create a static entry in the MAC address table.
SUMMARY STEPS
1. enable
2. configure terminal
3. mac-address-table static mac-address fastethernet interface-id [vlan vlan-id]
4. end
5. show mac-address-table
DETAILED STEPS
Example
Use the show mac command to verify the MAC address table, as illustrated below:
Router# show mac-address-table
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 Router(config)# mac-address-table static mac-address fastethernet interface-id [vlan vlan-id]
Example:Router(config)# mac-address-table static 00ff.ff0d.2dc0 fastethernet 0/1/1
Creates a static entry in the MAC address table.
When the vlan-id is not specified, VLAN 1 is taken by default.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show mac-address-table
Example:Router# show mac-address-table
Verifies the MAC address table.
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Destination Address Address Type VLAN Destination Port------------------- ------------ ---- --------------------00ff.ff0d.2dc0 Self 1 Vlan10007.ebc7.ff84 Static 1 FastEthernet0/3/50007.ebc8.018b Static 1 FastEthernet0/3/6000b.bf94.0006 Static 1 FastEthernet0/3/3000b.bf94.0038 Static 1 FastEthernet0/3/0000b.bf94.0039 Static 1 FastEthernet0/3/1000b.bf94.0008 Static 314 FastEthernet0/3/2000b.bf94.0038 Static 314 FastEthernet0/3/0000b.bf94.0008 Static 331 FastEthernet0/3/2000b.bf94.0038 Static 331 FastEthernet0/3/0000b.bf94.0008 Static 348 FastEthernet0/3/2000b.bf94.0038 Static 348 FastEthernet0/3/0
Configuring and Verifying the Aging Timer
The aging timer may be configured from 16 seconds to 4080 seconds, in 16-second increments.
Follow these steps to configure the aging timer.
SUMMARY STEPS
1. enable
2. configure terminal
3. mac-address-table aging-time time
4. end
5. show mac-address-table aging-time
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 mac-address-table aging-time time
Example:Router(config)# mac-address-table aging-time 4080
Configures the MAC address aging timer age in seconds.
• The range is 0 to 10000 seconds.
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Example
Use the show mac-address-table aging-time command to verify the MAC address table aging timer, as illustrated below:
Router # show mac-address-table aging-timeMac address aging time 320
Configuring Cisco Discovery Protocol• Enabling Cisco Discovery Protocol, page 131
• Enabling CDP on an Interface, page 132
• Monitoring and Maintaining CDP, page 134
Enabling Cisco Discovery Protocol
To enable Cisco Discovery Protocol (CDP) globally, use the following commands.
SUMMARY STEPS
1. enable
2. configure terminal
3. cdp run
4. end
5. show cdp
DETAILED STEPS
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show mac-address-table aging-time
Example:Router# show mac-address-table aging-time
Verifies the MAC address table.
Command or Action Purpose
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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Example
Use the show cdp command to verify the CDP configuration:
Router# show cdp
Global CDP information: Sending CDP packets every 120 seconds Sending a holdtime value of 180 seconds Sending CDPv2 advertisements is enabledRouter#
Enabling CDP on an Interface
Use the steps below to enable CDP on an interface.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet}
4. cdp enable
5. end
6. show cdp interface interface-id
7. show cdp neighbors
Step 3 cdp run
Example:Router(config)# cdp run
Enables CDP globally.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show cdp
Example:Router# show cdp
Verifies the CDP configuration.
Command or Action Purpose
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DETAILED STEPS
Example
Use the show cdp command to verify the CDP configuration for an interface.
Router# show cdp interface fastethernet 0/1/1
FastEthernet0/1/1 is up, line protocol is up Encapsulation ARPA Sending CDP packets every 120 seconds Holdtime is 180 secondsRouter#
Router# show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - RepeaterDevice ID Local Intrfce Holdtme Capability Platform Port ID
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface {ethernet | fastethernet} interface-id
Example:Router(config)# interface fastethernet 0/1/1
Selects an interface to configure.
Step 4 cdp enable
Example:Router(config)# cdp enable
Enables CDP globally.
Step 5 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 6 show cdp interface interface-id
Example:Router# show cdp interface
Verifies the CDP configuration on the interface.
Step 7 show cdp neighbors
Example:Router# show cdp neighbors
Verifies the information about the neighboring equipment.
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tftp-switch Fas 0/0 125 R S I 2811 Fas 0/3/6hwic-3745-2 Fas 0/1/0 149 R S I 3745 Fas 0/1Router#
Monitoring and Maintaining CDP
Use the following commands to monitor and maintain CDP on your device.
SUMMARY STEPS
1. enable
2. clear cdp counters
3. clear cdp table
4. show cdp
5. show cdp entry entry-name [protocol | version]
6. show cdp interface interface-id
7. show cdp neighbors interface-id [detail]
8. show cdp traffic
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 clear cdp counters
Example:Router# clear cdp counters
(Optional) Resets the traffic counters to zero.
Step 3 clear cdp table
Example:Router# clear cdp table
(Optional) Deletes the CDP table of information about neighbors.
Step 4 show cdp
Example:Router# show cdp
(Optional) Verifies global information such as frequency of transmissions and the holdtime for packets being transmitted.
Step 5 show cdp entry entry_name [protocol | version]
Example:Router# show cdp entry newentry
(Optional) Verifies information about a specific neighbor.
• The display can be limited to protocol or version information.
Step 6 show cdp interface interface-id
Example:Router# show cdp interface 0/1/1
(Optional) Verifies information about interfaces on which CDP is enabled.
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Configuring the Switched Port Analyzer (SPAN) This section describes how to configure a switched port analyzer (SPAN) session for an EtherSwitch HWIC.
• Configuring the SPAN Sources, page 135
• Configuring SPAN Destinations, page 136
• Configuring Power Management on the Interface, page 137
Note An EtherSwitch HWIC supports only one SPAN session. Either Tx or both Tx and Rx monitoring is supported.
Configuring the SPAN Sources
Use the following task to configure the source for a SPAN session.
SUMMARY STEPS
1. enable
2. configure terminal
3. monitor session 1 {source {interface interface-id} | {vlan vlan-ID}} [, | - | rx | tx | both]
Step 7 show cdp neighbors interface-id [detail]
Example:Router# show cdp neighbors 0/1/1
(Optional) Verifies information about neighbors.
• The display can be limited to neighbors on a specific interface and can be expanded to provide more detailed information.
Step 8 show cdp traffic
Example:Router# show cdp traffic
(Optional) Verifies CDP counters, including the number of packets sent and received and checksum errors.
Command or Action Purpose
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DETAILED STEPS
Configuring SPAN Destinations
To configure the destination for a SPAN session, use the following commands.
SUMMARY STEPS
1. enable
2. configure terminal
3. monitor session session-id {destination {interface type interface-id} [, | -] | {vlan vlan-ID}}
4. show monitor session
5. no monitor session session-id
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 monitor session 1 {source {interface interface-id} | {vlan vlan-ID}} [, | - | rx | tx | both]
Example:Router(config)# monitor session 1 source interface fastethernet 0/3/1
Specifies the SPAN session (number 1), the source interfaces or VLANs, and the traffic direction to be monitored.
• The example shows how to configure the SPAN session to monitor bidirectional traffic from source interface Fast Ethernet 0/3/1.
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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Example
Use the show monitor session command to verify the sources and destinations configured for the SPAN session.
Router# show monitor session 1
Session 1 --------- Source Ports: RX Only: None TX Only: None Both: Fa0/1/0 Source VLANs: RX Only: None TX Only: None Both: None Destination Ports: Fa0/1/1 Filter VLANs: None
Configuring Power Management on the InterfaceThe HWICs can supply inline power to a Cisco 7960 IP phone, if necessary. The Cisco 7960 IP phone can also be connected to an AC power source and supply its own power to the voice circuit. When the Cisco 7960 IP phone is supplying its own power, an HWICs can forward IP voice traffic to and from the phone.
A detection mechanism on the HWIC determines whether it is connected to a Cisco 7960 IP phone. If the switch senses that there is no power on the circuit, the switch supplies the power. If there is power on the circuit, the switch does not supply it.
You can configure the switch never to supply power to the Cisco 7960 IP phone and to disable the detection mechanism.
Follow these steps to manage the powering of the Cisco IP phones.
Step 3 monitor session session-id {destination {interface interface-id} | {vlan vlan-ID}} [, | - | rx | tx | both]
Example:Router(config)# monitor session 1 source interface fastethernet 0/3/1
Specifies the SPAN session (number 1), the source interfaces or VLANs, and the traffic direction to be monitored.
• The example shows how to configure the SPAN session to monitor bidirectional traffic from source interface Fast Ethernet 0/3/1.
Step 4 show monitor session session-id
Example:Router(config)# show monitor session 1
Verifies the sources and destinations configured for the SPAN session.
Step 5 no monitor session session-id
Example:Router(config)# no monitor session 1
Clears existing SPAN configuration.
Command or Action Purpose
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SUMMARY STEPS
1. enable
2. configure terminal
3. interface fastethernet interface-id
4. power inline {auto | never}
5. end
6. show power inline
DETAILED STEPS
Example
Use the show power inline command to verify the power configuration on the ports, as illustrated below.
Router# show power inline
PowerSupply SlotNum. Maximum Allocated Status----------- -------- ------- --------- ------ INT-PS 0 120.000 101.500 PS GOOD
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface fastethernet interface-id
Example:Router(config)# interface fastethernet 0/3/1
Selects a particular Fast Ethernet interface for configuration.
Step 4 power inline {auto |never}
Example:Router(config-if)# power inline auto
Configures the port to supply inline power automatically to a Cisco IP phone.
• Use never to permanently disable inline power on the port.
Step 5 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 6 show power inline
Example:Router# show power inline
Displays power configuration on the ports.
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Interface Config Phone Powered PowerAllocated--------- ------ ----- ------- --------------Fa0/1/0 auto Cisco On 6.300 Watts Fa0/1/1 auto Cisco On 6.300 Watts Fa0/1/2 auto Cisco On 6.300 Watts Fa0/1/3 auto Cisco On 6.300 Watts Fa0/1/4 auto Cisco On 6.300 Watts Fa0/1/5 auto Cisco On 6.300 Watts Fa0/1/6 auto Cisco On 6.300 Watts Fa0/1/7 auto Cisco On 6.300 Watts Fa0/3/0 auto Cisco On 6.300 Watts Fa0/3/1 auto Cisco On 6.300 Watts Fa0/3/2 auto Cisco On 6.300 Watts Fa0/3/3 auto Cisco On 6.300 Watts Fa0/3/4 auto Cisco On 6.300 Watts Fa0/3/5 auto Cisco On 6.300 Watts Fa0/3/6 auto IEEE-2 On 7.000 Watts Fa0/3/7 auto Cisco On 6.300 Watts
Configuring IP Multicast Layer 3 SwitchingThese sections describe how to configure IP multicast Layer 3 switching:
• Enabling IP Multicast Routing Globally, page 139
• Enabling IP Protocol-Independent Multicast (PIM) on Layer 3 Interfaces, page 140
• Verifying IP Multicast Layer 3 Hardware Switching Summary, page 141
• Verifying the IP Multicast Routing Table, page 142
Enabling IP Multicast Routing Globally
You must enable IP multicast routing globally before you can enable IP multicast Layer 3 switching on Layer 3 interfaces.
For complete information and procedures, refer to these publications:
• Cisco IOS IP Configuration Guide, Release 12.2, at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fipr_c/
• Cisco IOS IP Command Reference, Volume 1 of 3: Addressing and Services, Release 12.2, at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fipras_r/index.htm
• Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols, Release 12.2, at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fiprrp_r/index.htm
• Cisco IOS IP Command Reference, Volume 3 of 3: Multicast, Release 12.2, at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fiprmc_r/index.htm
Use the following commands to enable IP multicast routing globally.
SUMMARY STEPS
1. enable
2. configure terminal
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3. ip multicast-routing
DETAILED STEPS
Enabling IP Protocol-Independent Multicast (PIM) on Layer 3 Interfaces
You must enable protocol-independent multicast (PIM) on the Layer 3 interfaces before enabling IP multicast Layer 3 switching functions on those interfaces.
Beginning in global configuration mode, follow these steps to enable IP PIM on a Layer 3 interface.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface vlan vlan-id
4. ip pim {dense-mode | sparse-mode | sparse-dense-mode}
DETAILED STEPS
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip multicast-routing
Example:Router(config)# ip multicast-routing
Enables IP multicast routing globally.
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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Examples
The following example shows how to enable PIM on an interface using the default mode (sparse-dense-mode):
Router(config-if)# ip pim sparse-dense modeRouter(config-if)#
The following example shows how to enable PIM sparse mode on an interface:
Router(config-if)# ip pim sparse-modeRouter(config-if)#
Verifying IP Multicast Layer 3 Hardware Switching Summary
Note The show interface statistics command does not verify hardware-switched packets, only packets switched by software.
The show ip pim interface count command verifies the IP multicast Layer 3 switching enable state on IP PIM interfaces and verifies the number of packets received and sent on the interface.
Use the following show commands to verify IP multicast Layer 3 switching information for an IP PIM Layer 3 interface.
Step 1 Router# show ip pim interface count
State:* - Fast Switched, D - Distributed Fast SwitchedH - Hardware Switching Enabled
Address Interface FS Mpackets In/Out10.0.0.1 VLAN1 * 151/0Router#
Step 2 Router# show ip mroute count
IP Multicast Statistics5 routes using 2728 bytes of memory4 groups, 0.25 average sources per groupForwarding Counts:Pkt Count/Pkts per second/Avg Pkt Size/Kilobits per secondOther counts:Total/RPF failed/Other drops(OIF-null, rate-limit etc) Group:209.165.200.225 Source count:1, Packets forwarded: 0, Packets received: 66 Source:10.0.0.2/32, Forwarding:0/0/0/0, Other:66/0/66Group:209.165.200.226, Source count:0, Packets forwarded: 0, Packets received: 0Group:209.165.200.227, Source count:0, Packets forwarded: 0, Packets received: 0Group:209.165.200.228, Source count:0, Packets forwarded: 0, Packets received: 0
Step 3 interface vlan vlan-id
Router(config)# interface vlan 1
Selects the interface to be configured.
Step 4 ip pim {dense-mode | sparse-mode | sparse-dense-mode}
Example:Router(config-if)# ip pim sparse-dense mode
Enables IP PIM on a Layer 3 interface.
Command Purpose
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Router#
Note A negative counter means that the outgoing interface list of the corresponding entry is NULL, and this indicates that this flow is still active.
Step 3 Router# show ip interface vlan 1
Vlan1 is up, line protocol is up Internet address is 10.0.0.1/24 Broadcast address is 209.165.201.1 Address determined by setup command MTU is 1500 bytes Helper address is not set Directed broadcast forwarding is disabled Multicast reserved groups joined:209.165.201.2 209.165.201.3 209.165.201.4 209.165.201.5 Outgoing access list is not set Inbound access list is not set Proxy ARP is enabled Local Proxy ARP is disabled Security level is default Split horizon is enabled ICMP redirects are always sent ICMP unreachables are always sent ICMP mask replies are never sent IP fast switching is enabled IP fast switching on the same interface is disabled IP Flow switching is disabled IP CEF switching is enabled IP CEF Fast switching turbo vector IP multicast fast switching is enabled IP multicast distributed fast switching is disabled IP route-cache flags are Fast, CEF Router Discovery is disabled IP output packet accounting is disabled IP access violation accounting is disabled TCP/IP header compression is disabled RTP/IP header compression is disabled Policy routing is disabled Network address translation is disabled WCCP Redirect outbound is disabled WCCP Redirect inbound is disabled WCCP Redirect exclude is disabled BGP Policy Mapping is disabledRouter#
Verifying the IP Multicast Routing Table
Use the show ip mroute command to verify the IP multicast routing table:
Router# show ip mroute 224.10.103.10
IP Multicast Routing TableFlags:D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected, L - Local, P - Pruned, R - RP-bit set, F - Register flag, T - SPT-bit set, J - Join SPT, M - MSDP created entry, X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement, U - URD, I - Received Source Specific Host Report, Z - Multicast Tunnel, Y - Joined MDT-data group, y - Sending to MDT-data groupOutgoing interface flags:H - Hardware switched, A - Assert winnerTimers:Uptime/ExpiresInterface state:Interface, Next-Hop or VCD, State/Mode
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(*, 209.165.201.2), 00:09:21/00:02:56, RP 0.0.0.0, flags:DC Incoming interface:Null, RPF nbr 0.0.0.0 Outgoing interface list: Vlan1, Forward/Sparse-Dense, 00:09:21/00:00:00, H
Router#
Note The RPF-MFD flag indicates that the flow is completely hardware switched. The H flag indicates that the flow is hardware-switched on the outgoing interface.
Configuring IGMP SnoopingThis section describes how to configure IGMP snooping on your router and consists of the following configuration information and procedures:
• Enabling or Disabling IGMP Snooping, page 143
• Enabling IGMP Immediate-Leave Processing, page 145
• Statically Configuring an Interface to Join a Group, page 146
• Configuring a Multicast Router Port, page 148
Enabling or Disabling IGMP Snooping
By default, IGMP snooping is globally enabled on the EtherSwitch HWIC. When globally enabled or disabled, it is also enabled or disabled in all existing VLAN interfaces. By default, IGMP snooping is enabled on all VLANs, but it can be enabled and disabled on a per-VLAN basis.
Global IGMP snooping overrides the per-VLAN IGMP snooping capability. If global snooping is disabled, you cannot enable VLAN snooping. If global snooping is enabled, you can enable or disable snooping on a VLAN basis.
Follow the steps below to globally enable IGMP snooping on the EtherSwitch HWIC.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip igmp snooping
4. end
5. show ip igmp snooping
6. copy running-config startup-config
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DETAILED STEPS
To globally disable IGMP snooping on all VLAN interfaces, use the no ip igmp snooping global command.
Use the following steps to enable IGMP snooping on a VLAN interface.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip igmp snooping vlan vlan-id
4. end
5. show ip igmp snooping
6. copy running-config startup-config
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip igmp snooping
Example:Router(config)# ip igmp snooping
Globally enables IGMP snooping in all existing VLAN interfaces.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show ip igmp snooping
Example:Router# show ip igmp snooping
Displays snooping configuration.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your configuration to the startup configuration.
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DETAILED STEPS
To disable IGMP snooping on a VLAN interface, use the no ip igmp snooping vlan vlan-id global configuration command for the specified VLAN number (for example, vlan1).
Enabling IGMP Immediate-Leave Processing
When you enable IGMP Immediate-Leave processing, the EtherSwitch HWIC immediately removes a port from the IP multicast group when it detects an IGMP version 2 Leave message on that port. Immediate-Leave processing allows the switch to remove an interface that sends a Leave message from the forwarding table without first sending out group-specific queries to the interface. You should use the Immediate-Leave feature only when there is only a single receiver present on every port in the VLAN.
Use the following steps to enable IGMP Immediate-Leave processing.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip igmp snooping vlan vlan-id immediate-leave
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip igmp snooping vlan vlan-id
Example:Router(config)# ip igmp snooping vlan 1
Enables IGMP snooping on the VLAN interface.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show ip igmp snooping [vlan vlan-id]
Example:Router# show ip igmp snooping vlan 1
Displays snooping configuration.
• (Optional) vlan-id is the number of the VLAN.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your configuration to the startup configuration.
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4. end
5. show ip igmp snooping
6. copy running-config startup-config
DETAILED STEPS
To disable Immediate-Leave processing, follow Steps 1 and 2 to enter interface configuration mode, and use the no ip igmp snooping vlan vlan-id immediate-leave global configuration command.
Statically Configuring an Interface to Join a Group
Ports normally join multicast groups through the IGMP report message, but you can also statically configure a host on an interface.
Follow the steps below to add a port as a member of a multicast group.
SUMMARY STEPS
1. enable
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip igmp snooping vlan vlan-id immediate-leave
Example:Router(config)# ip igmp snooping vlan 1 immediate-leave
Enables IGMP Immediate-Leave processing on the VLAN interface.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show ip igmp snooping
Example:Router# show ip igmp snooping
Displays snooping configuration.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your configuration to the startup configuration.
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2. configure terminal
3. ip igmp snooping vlan vlan-id static mac-address interface interface-id
4. end
5. show mac-address-table multicast [vlan vlan-id] [user | igmp-snooping] [count]
6. show igmp snooping
7. copy running-config startup-config
DETAILED STEPS
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip igmp snooping vlan vlan-id static mac-address interface interface-id
Example:Router(config)# ip igmp snooping vlan 1 static 0100.5e05.0505 interface Fa0/1/1
Enables IGMP snooping on the VLAN interface.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show mac-address-table multicast [vlan vlan-id] [user | igmp-snooping] [count]
Example:Router# show mac-address-table multicast vlan 1 igmp-snooping
Displays MAC address table entries for a VLAN.
• vlan-id is the multicast group VLAN ID.
• user displays only the user-configured multicast entries.
• igmp-snooping displays entries learned via IGMP snooping.
• count displays only the total number of entries for the selected criteria, not the actual entries.
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Configuring a Multicast Router Port
Follow the steps below to enable a static connection to a multicast router.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip igmp snooping vlan vlan-id mrouter {interface interface-id | learn pim-dvmrp}
4. end
5. show ip igmp snooping
6. show ip igmp snooping mrouter [vlan vlan-id]
7. copy running-config startup-config
DETAILED STEPS
Step 6 show ip igmp snooping
Example:Router# show ip igmp snooping
Displays snooping configuration.
Step 7 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your configuration to the startup configuration.
Command Purpose
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip igmp snooping vlan vlan-id mrouter {interface interface-id | learn pim-dvmrp}
Example:Router(config)# ip igmp snooping vlan1 interface Fa0/1/1 learn pim-dvmrp
Enables IGMP snooping on the VLAN interface and enables route discovery.
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Configuring Per-Port Storm ControlYou can use these techniques to block the forwarding of unnecessary flooded traffic. This section describes how to configure per-port storm control and characteristics on your router and consists of the following configuration procedures:
• Enabling Per-Port Storm Control, page 149
• Disabling Per-Port Storm Control, page 150
By default, unicast, broadcast, and multicast suppression is disabled.
Enabling Per-Port Storm Control
Use these steps to enable per-port storm control.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface interface-id
4. storm-control {broadcast | multicast | unicast} level level-high [level-low]
5. storm-control action shutdown
6. end
7. show storm-control [interface] [broadcast | multicast | unicast | history]
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show ip igmp snooping
Example:Router# show ip igmp snooping
Displays snooping configuration.
Step 6 show ip igmp snooping mrouter [vlan vlan-id]
Example:Router# show ip igmp snooping mroute vlan vlan1
Displays Mroute discovery information.
Step 7 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your configuration to the startup configuration.
Command Purpose
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DETAILED STEPS
Note If any type of traffic exceeds the upper threshold limit, all of the other types of traffic will be stopped.
Disabling Per-Port Storm Control
Follow these steps to disable per-port storm control.
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface interface-id
Example:Router(config)# interface 0/3/1
Enters interface configuration mode and specifies the port to configure.
Step 4 storm-control {broadcast | multicast | unicast} level level-high [level-low]
Example:Router(config-if)# Storm-control broadcast level 7
Configures broadcast, multicast, or unicast per-port storm control.
• Specify the rising threshold level for either broadcast, multicast, or unicast traffic. The storm control action occurs when traffic utilization reaches this level.
• (Optional) Specify the falling threshold level. The normal transmission restarts (if the action is filtering) when traffic drops below this level.
Step 5 storm-control action shutdown
Example:Router(config-if)# Storm-control action shutdown
Selects the shutdown keyword to disable the port during a storm.
• The default is to filter out the traffic.
Step 6 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 7 show storm-control [interface] [broadcast | multicast | unicast | history]
Example:Router(config-if)# show storm-control
Verifies your entries.
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SUMMARY STEPS
1. enable
2. configure terminal
3. interface interface-id
4. no storm-control {broadcast | multicast | unicast} level level-high [level-low]
5. no storm-control action shutdown
6. end
7. show storm-control {broadcast | multicast | unicast}
DETAILED STEPS
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface interface-id
Example:Router(config)# interface 0/3/1
Enters interface configuration mode and specifies the port to configure.
Step 4 no storm-control {broadcast | multicast | unicast} level level-high [level-low]
Example:Router(config-if)# no storm-control broadcast level 7
Disables per-port storm control.
Step 5 no storm-control action shutdown
Example:Router(config-if)# no storm-control action shutdown
Disables the specified storm control action.
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Configuring StackingStacking is the connection of two switch modules resident in the same chassis so that they behave as a single switch. When a chassis is populated with two switch modules, the user must configure both of them to operate in stacked mode. This is done by selecting one port from each switch module and configuring it to be a stacking partner. The user must then use a cable to connect the stacking partners from each switch module to physically stack the switch modules. Any one port in a switch module can be designated as the stacking partner for that switch module.
Follow the steps below to configure a pair of ports on two different switch modules as stacking partners.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface fastethernet interface-id
4. no shutdown
5. switchport stacking-partner interface FastEthernet partner-interface-id
6. exit
7. interface fastethernet partner-interface-id
8. no shutdown
9. end
Step 6 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 7 show storm-control [interface] [{broadcast | multicast | unicast | history}]
Example:Router(config-if)# show storm-control
Verifies your entries.
Command Purpose
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DETAILED STEPS
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface fastethernet interface-id
Example:Router# interface fastethernet 0/3/1
Enters interface configuration mode and specifies the port to configure.
Step 4 no shutdown
Example:Router# no shutdown
Activates the interface.
• This step is required only if you shut down the interface.
Step 5 switchport stacking-partner interface fastethernet partner-interface-id
Example:Router(config-if)# switchport stacking-partner interface FastEthernet partner-interface-id
Selects and configures the stacking partner port.
• To restore the defaults, use the no form of this command.
Step 6 exit
Example:Router(config-if)# exit
Returns to privileged configuration mode.
Step 7 interface fastethernet partner-interface-id
Example:Router# interface fastethernet 0/3/1
Enters interface configuration mode and specifies the partner-interface.
Step 8 no shutdown
Example:Router(config)# no shutdown
Activates the stacking partner interface.
Step 9 end
Example:Router(config)# end
Exits configuration mode.
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Note Both stacking partner ports must have their speed and duplex parameters set to auto.
Caution If stacking is removed, stacked interfaces will go to shutdown state. Other nonstacked ports will be left unchanged.
Configuring Fallback BridgingThis section describes how to configure fallback bridging on your switch. It contains this configuration information:
• Understanding the Default Fallback Bridging Configuration, page 154
• Creating a Bridge Group, page 155
• Preventing the Forwarding of Dynamically Learned Stations, page 156
• Configuring the Bridge Table Aging Time, page 158
• Filtering Frames by a Specific MAC Address, page 159
• Adjusting Spanning-Tree Parameters, page 160
• Monitoring and Maintaining the Network, page 169
Understanding the Default Fallback Bridging Configuration
Table 9 shows the default fallback bridging configuration.
Table 9 Default Fallback Bridging Configuration
Feature Default Setting
Bridge groups None are defined or assigned to an interface. No VLAN-bridge STP is defined.
Switch forwards frames for stations that it has dynamically learned
Enabled.
Bridge table aging time for dynamic entries 300 seconds.
MAC-layer frame filtering Disabled.
Spanning tree parameters:
• Switch priority
• Interface priority
• Interface path cost
• Hello BPDU interval
• Forward-delay interval
• Maximum idle interval
• 32768
• 128
• 10 Mbps: 100100 Mbps: 191000 Mbps: 4
• 2 seconds
• 20 seconds
• 30 seconds
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Creating a Bridge Group
To configure fallback bridging for a set of switched virtual interfaces (SVIs), these interfaces must be assigned to bridge groups. All interfaces in the same group belong to the same bridge domain. Each SVI can be assigned to only one bridge group.
Follow the steps below to create a bridge group and assign an interface to it.
SUMMARY STEPS
1. enable
2. configure terminal
3. no ip routing
4. bridge bridge-group protocol vlan-bridge
5. interface interface-id
6. bridge-group bridge-group
7. end
8. show vlan-bridge
9. show running-config
10. copy running-config startup-config
DETAILED STEPS
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 no ip routing
Example:Router(config)# no ip routing
Disables IP routing.
Step 4 bridge bridge-group protocol vlan-bridge
Example:Router(config)# bridge 100 protocol vlan-bridge
Assigns a bridge group number and specifies the VLAN-bridge spanning-tree protocol to run in the bridge group.
• The ibm and dec keywords are not supported.
• For bridge-group, specify the bridge group number. The range is 1 to 255.
• Frames are bridged only among interfaces in the same group.
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To remove a bridge group, use the no bridge bridge-group protocol vlan-bridge global configuration command. To remove an interface from a bridge group, use the no bridge-group bridge-group interface configuration command.
Preventing the Forwarding of Dynamically Learned Stations
By default, the switch forwards any frames for stations that it has dynamically learned. When this activity is disabled , the switch only forwards frames whose addresses have been statically configured into the forwarding cache.
Follow the steps below to prevent the switch from forwarding frames for stations that it has dynamically learned.
SUMMARY STEPS
1. enable
2. configure terminal
3. no bridge bridge-group acquire
Step 5 interface interface-id
Example:Router(config)# interface 0/3/1
Enters interface configuration mode and specifies the interface on which you want to assign the bridge group.
• The specified interface must be an SVI: a VLAN interface that you created by using the interface vlan vlan-id global configuration command.
• These ports must have IP addresses assigned to them.
Step 6 bridge-group bridge-group
Example:Router(config-if)# bridge-group 100
Assigns the interface to the bridge group created in Step 2.
• By default, the interface is not assigned to any bridge group. An interface can be assigned to only one bridge group.
Step 7 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 8 show vlan-bridge
Example:Router# show vlan-bridge
(Optional) Verifies forwarding mode.
Step 9 show running-config
Example:Router# show running-config
(Optional) Verifies your entries.
Step 10 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entries in the configuration file.
Command Purpose
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4. end
5. show running-config
6. copy running-config startup-config
DETAILED STEPS
To cause the switch to forward frames to stations that it has dynamically learned, use the bridge bridge-group acquire global configuration command.
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 no bridge bridge-group acquire
Example:Router(config)# no bridge 100 acquire
Enables the switch to stop forwarding any frames for stations that it has dynamically learned through the discovery process and to limit frame forwarding to statically configured stations.
• The switch filters all frames except those whose destined-to addresses have been statically configured into the forwarding cache. To configure a static address, use the bridge bridge-group address mac-address {forward | discard} global configuration command.
• For bridge-group, specify the bridge group number. The range is 1 to 255.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show running-config
Example:Router# show running-config
Verifies your entry.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entry in the configuration file.
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Configuring the Bridge Table Aging Time
A switch forwards, floods, or drops packets based on the bridge table. The bridge table maintains both static and dynamic entries. Static entries are entered by you. Dynamic entries are entered by the bridge learning process. A dynamic entry is automatically removed after a specified length of time, known as aging time, from the time the entry was created or last updated.
If you are likely to move hosts on a switched network, decrease the aging time to enable the switch to quickly adapt to the change. If hosts on a switched network do not continuously send packets, increase the aging time to keep the dynamic entries for a longer time and thus reduce the possibility of flooding when the hosts send again.
Follow the steps below to configure the aging time.
SUMMARY STEPS
1. enable
2. configure terminal
3. bridge bridge-group aging-time seconds
4. end
5. show running-config
6. copy running-config startup-config
DETAILED STEPS
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 bridge bridge-group aging-time seconds
Example:Router(config)# bridge 100 aging-time 10000
Specifies the length of time that a dynamic entry remains in the bridge table from the time the entry was created or last updated.
• For bridge-group, specify the bridge group number. The range is 1 to 255.
• For seconds, enter a number from 0 to 1000000. The default is 300 seconds.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
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To return to the default aging-time interval, use the no bridge bridge-group aging-time global configuration command.
Filtering Frames by a Specific MAC Address
A switch examines frames and sends them through the internetwork according to the destination address; a switch does not forward a frame back to its originating network segment. You can use the software to configure specific administrative filters that filter frames based on information other than the paths to their destinations.
You can filter frames with a particular MAC-layer station destination address. Any number of addresses can be configured in the system without a performance penalty.
Follow the steps below to filter by the MAC-layer address.
SUMMARY STEPS
1. enable
2. configure terminal
3. bridge bridge-group address mac-address {forward | discard} [interface-id]
4. end
5. show running-config
6. copy running-config startup-config
DETAILED STEPS
Step 5 show running-config
Example:Router# show running-config
Verifies your entry.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entry in the configuration file.
Command Purpose
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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To disable the frame forwarding ability, use the no bridge bridge-group address mac-address global configuration command.
Adjusting Spanning-Tree Parameters
You might need to adjust certain spanning-tree parameters if the default values are not suitable for your switch configuration. Parameters affecting the entire spanning tree are configured with variations of the bridge global configuration command. Interface-specific parameters are configured with variations of the bridge-group interface configuration command.
You can adjust spanning-tree parameters by performing any of the tasks in these sections:
• Changing the Switch Priority, page 160
• Changing the Interface Priority, page 162
• Assigning a Path Cost, page 163
• Adjusting BPDU Intervals, page 164
• Adjusting the Interval Between Hello BPDUs, page 164
• Changing the Forward-Delay Interval, page 165
• Changing the Maximum-Idle Interval, page 166
• Disabling the Spanning Tree on an Interface, page 168
Note Only network administrators with a good understanding of how switches and STP function should make adjustments to spanning-tree parameters. Poorly planned adjustments can have a negative impact on performance. A good source on switching is the IEEE 802.1d specification; for more information, refer to the “References and Recommended Reading” appendix in the Cisco IOS Configuration Fundamentals Command Reference, Release 12.2.
Changing the Switch Priority
You can globally configure the priority of an individual switch when two switches tie for position as the root switch, or you can configure the likelihood that a switch will be selected as the root switch. This priority is determined by default; however, you can change it.
Follow the steps below to change the switch priority.
Step 3 show running-config
Example:Router: show running-config
Verifies your entry.
Step 4 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entry in the configuration file.
Command Purpose
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SUMMARY STEPS
1. enable
2. configure terminal
3. bridge bridge-group priority number
4. end
5. show running-config
6. copy running-config startup-config
DETAILED STEPS
This command does not have a no form. To return to the default setting, use the bridge bridge-group priority number global configuration command, and set the priority to the default value. To change the priority on an interface, use the bridge-group priority interface configuration command (described in the next section).
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 bridge bridge-group priority number
Example:Router(config)# bridge 100 priority 5
Changes the priority of the switch.
• For bridge-group, specify the bridge group number. The range is 1 to 255.
• For number, enter a number from 0 to 65535. The default is 32768. The lower the number, the more likely the switch will be chosen as the root.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Step 5 show running-config
Example:Router: show running-config
Verifies your entry.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entry in the configuration file.
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Changing the Interface Priority
You can change the priority for an interface. When two switches tie for position as the root switch, you configure an interface priority to break the tie. The switch with the lower interface value is elected.
Follow the steps below to change the interface priority.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface interface-id
4. bridge-group bridge-group priority number
5. end
6. show running-config
7. copy running-config startup-config
DETAILED STEPS
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface interface-id
Example:Router(config)# interface 0/3/1
Enters interface configuration mode and specifies the interface to set the priority.
Step 4 bridge bridge-group priority number
Example:Router(config-if)# bridge 100 priority 4
Changes the prioriyt of the bridge.
Step 5 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
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To return to the default setting, use the bridge-group bridge-group priority number interface configuration command.
Assigning a Path Cost
Each interface has a path cost associated with it. By convention, the path cost is 1000/data rate of the attached LAN, in Mbps.
Follow the steps below to assign a path cost.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface interface-id
4. bridge-group bridge-group path-cost cost
5. end
6. show running-config
7. copy running-config startup-config
DETAILED STEPS
Step 6 show running-config
Example:Router: show running-config
Verifies your entry.
Step 7 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entry in the configuration file.
Command Purpose
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface interface-id
Example:Router(config)# interface 0/3/1
Enters interface configuration mode and specifies the interface to set the priority.
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To return to the default path cost, use the no bridge-group bridge-group path-cost cost interface configuration command.
Adjusting BPDU Intervals
You can adjust bridge protocol data unit (BPDU) intervals as described in these sections:
• Adjusting the Interval Between Hello BPDUs, page 164
• Changing the Forward-Delay Interval, page 165
• Changing the Maximum-Idle Interval, page 166
Note Each switch in a spanning tree adopts the interval between hello BPDUs, the forward delay interval, and the maximum idle interval parameters of the root switch, regardless of what its individual configuration might be.
Adjusting the Interval Between Hello BPDUs
Follow the steps below to adjust the interval between hello BPDUs.
SUMMARY STEPS
1. enable
2. configure terminal
3. bridge bridge-group hello-time seconds
4. end
5. show running-config
Step 4 bridge bridge-group path-costs cost
Example:Router(config-if)# bridge 100 pathcost 4
Changes the path cost.
Step 5 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 6 show running-config
Example:Router: show running-config
Verifies your entry.
Step 7 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entry in the configuration file.
Command Purpose
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6. copy running-config startup-config
DETAILED STEPS
To return to the default setting, use the no bridge bridge-group hello-time global configuration command.
Changing the Forward-Delay Interval
The forward-delay interval is the amount of time spent listening for topology change information after an interface has been activated for switching and before forwarding actually begins.
Follow the steps below to change the forward-delay interval.
SUMMARY STEPS
1. enable
2. configure terminal
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 bridge bridge-group hello-time seconds
Example:Router(config-if)# bridge 100 hello-time 5
Specifies the interval between hello BPDUs.
• For bridge-group, specify the bridge group number. The range is 1 to 255.
• For seconds, enter a number from 1 to 10. The default is 2 seconds.
Step 4 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 5 show running-config
Example:Router: show running-config
Verifies your entry.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entry in the configuration file.
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3. bridge bridge-group forward-time seconds
4. end
5. show running-config
6. copy running-config startup-config
DETAILED STEPS
To return to the default setting, use the no bridge bridge-group forward-time seconds global configuration command.
Changing the Maximum-Idle Interval
If a switch does not hear BPDUs from the root switch within a specified interval, it recomputes the spanning-tree topology.
Follow the steps below to change the maximum-idle interval (maximum aging time).
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 bridge bridge-group forward-time seconds
Example:Router(config-if)# bridge 100 forward-time 25
Specifies the forward-delay interval.
• For bridge-group, specify the bridge group number. The range is 1 to 255.
• For seconds, enter a number from 10 to 200. The default is 20 seconds.
Step 4 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 5 show running-config
Example:Router: show running-config
Verifies your entry.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entry in the configuration file.
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SUMMARY STEPS
1. enable
2. configure terminal
3. bridge bridge-group max-age seconds
4. end
5. show running-config
6. copy running-config startup-config
DETAILED STEPS
To return to the default setting, use the no bridge bridge-group max-age global configuration command.
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 bridge bridge-group max-age seconds
Example:Router(config-if)# bridge 100 forward-time 25
Specifies the interval the switch waits to hear BPDUs from the root switch.
• For bridge-group, specify the bridge group number. The range is 1 to 255.
• For seconds, enter a number from 10 to 200. The default is 30 seconds.
Step 4 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
Step 5 show running-config
Example:Router: show running-config
Verifies your entry.
Step 6 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entry in the configuration file.
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Disabling the Spanning Tree on an Interface
When a loop-free path exists between any two switched subnetworks, you can prevent BPDUs generated in one switching subnetwork from impacting devices in the other switching subnetwork, yet still permit switching throughout the network as a whole. For example, when switched LAN subnetworks are separated by a WAN, BPDUs can be prevented from traveling across the WAN link.
Follow the steps below to disable spanning tree on an interface.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface interface-id
4. bridge-group bridge-group spanning-disabled
5. end
6. show running-config
7. copy running-config startup-config
DETAILED STEPS
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface interface-id
Example:Router(config)# interface 0/3/1
Enters interface configuration mode and specifies the interface to set the priority.
Step 4 bridge-group bridge-group spanning-disabled
Example:Router(config-if)# bridge 100 spanning-disabled
Disables spanning tree on the interface.
• For bridge-group, specify the bridge group number. The range is 1 to 255.
Step 5 end
Example:Router(config-if)# end
Returns to privileged EXEC mode.
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To reenable spanning tree on the interface, use the no bridge-group bridge-group spanning-disabled interface configuration command.
Monitoring and Maintaining the Network
To monitor and maintain the network, use one or more of the following privileged EXEC commands.
Configuring Separate Voice and Data SubnetsFor ease of network administration and increased scalability, network managers can configure the HWICs to support Cisco IP phones such that the voice and data traffic reside on separate subnets. You should always use separate VLANs when you are able to segment the existing IP address space of your branch office.
User priority bits in the 802.1p portion of the 802.1Q standard header are used to provide prioritization in Ethernet switches. This is a vital component in designing Cisco AVVID networks.
The HWICs provides the performance and intelligent services of Cisco IOS software for branch office applications. The HWICs can identify user applications—such as voice or multicast video—and classify traffic with the appropriate priority levels.
Note Refer to the Cisco AVVID QoS Design Guide for more information on how to implement end-to-end QoS as you deploy Cisco AVVID solutions.
Follow these steps to automatically configure Cisco IP phones to send voice traffic on the voice VLAN ID (VVID) on a per-port basis (see the “Voice Traffic and VVID” section on page 170).
Step 6 show running-config
Example:Router: show running-config
Verifies your entry.
Step 7 copy running-config startup-config
Example:Router# copy running-config startup-config
(Optional) Saves your entry in the configuration file.
Command Purpose
Command Purpose
clear bridge bridge-group Removes any learned entries from the forwarding database and clears the transmit and receive counts for any statically configured entries.
show bridge [bridge-group] Displays details about the bridge group.
show bridge [bridge-group] [interface-id] [address] [group] [verbose]
Displays classes of entries in the bridge forwarding database.
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SUMMARY STEPS
1. enable
2. configure terminal
3. interface interface-id
4. switchport mode trunk
5. switchport voice vlan vlan-id
DETAILED STEPS
Voice Traffic and VVID
The HWICs can automatically configure voice VLAN. This capability overcomes the management complexity of overlaying a voice topology onto a data network while maintaining the quality of voice traffic. With the automatically configured voice VLAN feature, network administrators can segment phones into separate logical networks, even though the data and voice infrastructure is physically the same. The voice VLAN feature places the phones into their own VLANs without the need for end-user intervention. A user can plug the phone into the switch, and the switch provides the phone with the necessary VLAN information.
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface interface-id
Example:Router(config)# interface 0/2/1
Enters the interface configuration mode and the port to be configured (for example, interface fa0/3/1).
Step 4 switchport mode trunk
Example:Router(config-if)# switchport mode trunk
Configures the port to trunk mode.
Step 5 switchport voice vlan vlan-id
Example:Router(config-if)# switchport voice vlan 100
Configures the voice port with a VVID that will be used exclusively for voice traffic.
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Configuring a Single Subnet for Voice and Data
For network designs with incremental IP telephony deployment, network managers can configure the HWICs so that the voice and data traffic coexist on the same subnet. This might be necessary when it is impractical either to allocate an additional IP subnet for IP phones or to divide the existing IP address space into an additional subnet at the remote branch, it might be necessary to use a single IP address space for branch offices. (This is one of the simpler ways to deploy IP telephony.)
This configuration approach must address two key considerations:
• Network managers should ensure that existing subnets have enough available IP addresses for the new Cisco IP phones, each of which requires a unique IP address.
• Administering a network with a mix of IP phones and workstations on the same subnet might pose a challenge.
Beginning in privileged EXEC mode, follow these steps to automatically configure Cisco IP phones to send voice and data traffic on the same VLAN.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface interface-id
4. switchport access vlan vlan-id
5. end
DETAILED STEPS
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface interface-id
Example:Router(config)# interface 0/2/1
Enters the interface configuration mode and the port to be configured (e.g., interface fa0/1/1).
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Verifying Switchport Configuration
Use the show run interface command to verify the switchport configuration.
Router# show run interface interface-id
Use the write memory command to save the current configuration in flash memory.
Router# write memory
Managing the EtherSwitch HWICThis section describes how to perform basic management tasks on the HWICs with the Cisco IOS command line interface. You might find this information useful when you configure the switch for the purposed described in the preceding sections.
The following topics are included:
• Adding Trap Managers, page 172
• Configuring IP Information, page 173
• Enabling Switch Port Analyzer, page 177
• Managing the ARP Table, page 178
• Managing the MAC Address Tables, page 178
• Removing Dynamic Addresses, page 180
• Adding Secure Addresses, page 181
• Configuring Static Addresses, page 183
• Clearing All MAC Address Tables, page 185
Adding Trap Managers
A trap manager is a management station that receives and processes traps. When you configure a trap manager, community strings for each member switch must be unique. If a member switch has an IP address assigned to it, the management station accesses the switch by using its assigned IP address.
By default, no trap manager is defined, and no traps are issued.
Follow these steps to add a trap manager and community string.
Step 4 switchport access vlan vlan-id
Example:Router(config-if)# switchport access vlan 100
Sets the native VLAN for untagged traffic.
• The value of vlan-id represents the ID of the VLAN that is sending and receiving untagged traffic on the port. Valid IDs are from 1 to 1001. Leading zeroes are not permitted.
Step 5 end
Example:Router# end
Returns to the privileged EXEC mode.
Command Purpose
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SUMMARY STEPS
1. enable
2. configure terminal
3. snmp-server host ip-address traps snmp vlan-membership
4. end
DETAILED STEPS
Verifying Trap Managers
Use the show running-config command to verify that the information was entered correctly by displaying the running configuration:
Router# show running-config
Configuring IP Information
This section describes how to assign IP information on the HWICs. The following topics are included:
• Assigning IP Information to the Switch, page 173
• Specifying a Domain Name and Configuring the DNS, page 176
Assigning IP Information to the Switch
You can use a BOOTP server to automatically assign IP information to the switch; however, the BOOTP server must be set up in advance with a database of physical MAC addresses and corresponding IP addresses, subnet masks, and default gateway addresses. In addition, the switch must be able to access the BOOTP server through one of its ports. At startup, a switch without an IP address requests the
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 snmp-server host ip-address traps snmp vlan-membership
Example:Router(config)# snmp-server host 172.16.128.263 traps1 snmp vlancommunity1
Enters the trap manager IP address, community string, and the traps to generate.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
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information from the BOOTP server; the requested information is saved in the switch running the configuration file. To ensure that the IP information is saved when the switch is restarted, save the configuration by entering the write memory command in privileged EXEC mode.
You can change the information in these fields. The mask identifies the bits that denote the network number in the IP address. When you use the mask to subnet a network, the mask is then referred to as a subnet mask. The broadcast address is reserved for sending messages to all hosts. The CPU sends traffic to an unknown IP address through the default gateway.
Follow these steps to enter the IP information.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface vlan_id
4. ip address ip-address subnet-mask
5. exit
6. ip default-gateway ip-address
7. end
DETAILED STEPS
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface vlan_id
Example:Router(config)# interface vlan 1
Enters interface configuration mode and specifies the VLAN to which the IP information is assigned.
• VLAN 1 is the management VLAN, but you can configure any VLAN from IDs 1 to 1001.
Step 4 ip address ip-address subnet-mask
Example:Router(config)# ip address 192.0.2.10 255.255.255.255
Enters the IP address and subnet mask.
Step 5 exit
Example:Router(config)# exit
Returns to global configuration mode.
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Use the following procedure to remove the IP information from a switch.
Note Using the no ip address command in configuration mode disables the IP protocol stack and removes the IP information. Cluster members without IP addresses rely on the IP protocol stack being enabled.
Use these steps to remove an IP address.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface vlan_id
4. no ip address
5. end
DETAILED STEPS
Step 6 ip default-gateway ip-address
Example:Router# ip default-gateway 192.0.2.20
Enters the IP address of the default router.
Step 7 end
Example:Router# end
Returns to privileged EXEC mode.
Command Purpose
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface vlan_id
Example:Router(config)# interface vlan 1
Enters interface configuration mode, and enters the VLAN to which the IP information is assigned. VLAN 1 is the management VLAN, but you can configure any VLAN from IDs 1 to 1001.
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Caution If you are removing the IP address through a telnet session, your connection to the switch will be lost.
Specifying a Domain Name and Configuring the DNS
Each unique IP address can have a host name associated with it. The Cisco IOS software maintains an EXEC mode and related Telnet support operations. This cache speeds the process of converting names to addresses.
IP defines a hierarchical naming scheme that allows a device to be identified by its location or domain. Domain names are pieced together with periods (.) as the delimiting characters. For example, Cisco Systems is a commercial organization that IP identifies by a com domain name, so its domain name is cisco.com. A specific device in this domain, the FTP system, for example, is identified as ftp.cisco.com.
To track domain names, IP has defined the concept of a domain name server (DNS), the purpose of which is to hold a cache (or database) of names mapped to IP addresses. To map domain names to IP addresses, you must first identify the host names and then specify a name server and enable the DNS, the Internet’s global naming scheme that uniquely identifies network devices.
Specifying the Domain Name
You can specify a default domain name that the software uses to complete domain name requests. You can specify either a single domain name or a list of domain names. When you specify a domain name, any IP host name without a domain name has that domain name appended to it before being added to the host table.
Specifying a Name Server
You can specify up to six hosts that can function as a name server to supply name information for the DNS.
Enabling the DNS
If your network devices require connectivity with devices in networks for which you do not control name assignment, you can assign device names that uniquely identify your devices within the entire internetwork. The Internet’s global naming scheme, the DNS, accomplishes this task. This service is enabled by default.
Step 4 no ip address
Example:Router(config-subif)# no ip address
Removes the IP address and subnet mask.
Step 5 end
Example:Router(config-subif)# end
Returns to privileged EXEC mode.
Command Purpose
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Enabling Switch Port Analyzer
You can monitor traffic on a given port by forwarding incoming and outgoing traffic on the port to another port in the same VLAN. A Switch Port Analyzer (SPAN) port cannot monitor ports in a different VLAN, and a SPAN port must be a static-access port. Any number of ports can be defined as SPAN ports, and any combination of ports can be monitored. SPAN is supported for up to 2 sessions.
Follow the steps below to enable SPAN.
SUMMARY STEPS
1. enable
2. configure terminal
3. monitor session session-id {destination | source} {interface | vlan interface-id | vlan-id}} [, | - | both | tx | rx]
4. end
DETAILED STEPS
Disabling SPAN
Follow these steps to disable SPAN.
SUMMARY STEPS
1. enable
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 monitor session session-id {destination | source} {interface | vlan interface-id | vlan-id}} [, | - | both | tx | rx]
Example:Router(config)# monitor session session-id {destination | source} {interface | vlan interface-id | vlan-id}} [, | - | both | tx | rx]
Enables port monitoring for a specific session (“number”).
• Optionally, supply a SPAN destination interface and a source interface.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
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2. configure terminal
3. no monitor session session-id
4. end
DETAILED STEPS
Managing the ARP Table
To communicate with a device (on Ethernet, for example), the software first must determine the 48-bit MAC or local data link address of that device. The process of determining the local data link address from an IP address is called address resolution.
The Address Resolution Protocol (ARP) associates a host IP address with the corresponding media or MAC addresses and VLAN ID. Taking an IP address as input, ARP determines the associated MAC address. Once a MAC address is determined, the IP-MAC address association is stored in an ARP cache for rapid retrieval. Then the IP datagram is encapsulated in a link-layer frame and sent over the network. Encapsulation of IP datagrams and ARP requests and replies on IEEE 802 networks other than Ethernet is specified by the Subnetwork Access Protocol (SNAP). By default, standard Ethernet-style ARP encapsulation (represented by the arpa keyword) is enabled on the IP interface.
When you manually add entries to the ARP table by using the CLI, you must be aware that these entries do not age and must be manually removed.
Managing the MAC Address Tables
This section describes how to manage the MAC address tables on the HWICs. The following topics are included:
• Understanding MAC Addresses and VLANs, page 179
• Changing the Address Aging Time, page 179
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 no monitor session session-id
Example:Router(config)# no monitor session 37
Disables port monitoring for a specific session.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
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• Configuring the Aging Time, page 179
• Verifying Aging-Time Configuration, page 180
The switch uses the MAC address tables to forward traffic between ports. All MAC addresses in the address tables are associated with one or more ports. These MAC tables include the following types of addresses:
• Dynamic address—A source MAC address that the switch learns and then drops when it is not in use.
• Secure address—A manually entered unicast address that is usually associated with a secured port. Secure addresses do not age.
• Static address—A manually entered unicast or multicast address that does not age and that is not lost when the switch resets.
The address tables list the destination MAC address and the associated VLAN ID, module, and port number associated with the address. The following shows an example of a list of addresses as they would appear in the dynamic, secure, or static address table.
Router# show mac-address-table
Destination Address Address Type VLAN Destination Port------------------- ------------ ---- --------------------000a.000b.000c Secure 1 FastEthernet0/1/8000d.e105.cc70 Self 1 Vlan100aa.00bb.00cc Static 1 FastEthernet0/1/0
Understanding MAC Addresses and VLANs
All addresses are associated with a VLAN. An address can exist in more than one VLAN and have different destinations in each. Multicast addresses, for example, could be forwarded to port 1 in VLAN 1 and ports 9, 10, and 11 in VLAN 5.
Each VLAN maintains its own logical address table. A known address in one VLAN is unknown in another until it is learned or statically associated with a port in the other VLAN. An address can be secure in one VLAN and dynamic in another. Addresses that are statically entered in one VLAN must be static addresses in all other VLANs.
Changing the Address Aging Time
Dynamic addresses are source MAC addresses that the switch learns and then drops when they are not in use. Use the Aging Time field to define how long the switch retains unseen addresses in the table. This parameter applies to all VLANs.
Configuring the Aging Time
Setting too short an aging time can cause addresses to be prematurely removed from the table. Then when the switch receives a packet for an unknown destination, it floods the packet to all ports in the same VLAN as the receiving port. This unnecessary flooding can impact performance. Setting too long an aging time can cause the address table to be filled with unused addresses; it can cause delays in establishing connectivity when a workstation is moved to a new port.
Follow these steps to configure the dynamic address table aging time.
SUMMARY STEPS
1. enable
2. configure terminal
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3. mac-address-table aging-time seconds
4. end
DETAILED STEPS
Verifying Aging-Time Configuration
Use the show mac-address-table aging-time command to verify configuration:
Router# show mac-address-table aging-time
Removing Dynamic Addresses
Follow these steps to remove a dynamic address entry.
SUMMARY STEPS
1. enable
2. configure terminal
3. no mac-address-table dynamic hw-addr
4. end
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 mac-address-table aging-time seconds
Example:Router(config)# mac-address-table aging-time 30000
Enters the number of seconds that dynamic addresses are to be retained in the address table.
• Valid entries are from 10 to 1000000.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
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DETAILED STEPS
You can remove all dynamic entries by using the clear mac-address-table dynamic command in privileged EXEC mode.
Verifying Dynamic Addresses
Use the show mac-address-table dynamic command to verify configuration:
Router# show mac-address-table dynamic
Adding Secure Addresses
The secure address table contains secure MAC addresses and their associated ports and VLANs. A secure address is a manually entered unicast address that is forwarded to only one port per VLAN. If you enter an address that is already assigned to another port, the switch reassigns the secure address to the new port.
You can enter a secure port address even when the port does not yet belong to a VLAN. When the port is later assigned to a VLAN, packets destined for that address are forwarded to the port.
Follow these steps to add a secure address.
SUMMARY STEPS
1. enable
2. configure terminal
3. mac-address-table secure address hw-addr interface interface-id vlan vlan-id
4. end
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 no mac-address-table dynamic hw-addr
Example:Router(config)# no mac-address-table dynamic 0100.5e05.0505
Enters the MAC address to be removed from dynamic MAC address table.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
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DETAILED STEPS
Follow these steps to remove a secure address.
SUMMARY STEPS
1. enable
2. configure terminal
3. no mac-address-table secure hw-addr vlan vlan-id
4. end
DETAILED STEPS
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 mac-address-table secure address hw-addr interface interface-id vlan vlan-id
Example:Router(config)# mac-address-table secure address 0100.5e05.0505 interface 0/3/1 vlan vlan 1
Enters the MAC address, its associated port, and the VLAN ID.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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You can remove all secure addresses by using the clear mac-address-table secure command in privileged EXEC mode.
Verifying Secure Addresses
Use the show mac-address-table secure command to verify configuration:
Router# show mac-address-table secure
Configuring Static Addresses
A static address has the following characteristics:
• It is manually entered in the address table and must be manually removed.
• It can be a unicast or multicast address.
• It does not age and is retained when the switch restarts.
Because all ports are associated with at least one VLAN, the switch acquires the VLAN ID for the address from the ports that you select on the forwarding map. A static address in one VLAN must be a static address in other VLANs. A packet with a static address that arrives on a VLAN where it has not been statically entered is flooded to all ports and not learned.
Follow these steps to add a static address.
SUMMARY STEPS
1. enable
2. configure terminal
3. mac-address-table static hw-addr [interface] interface-id [vlan] vlan-id
4. end
Step 3 no mac-address-table secure hw-addr vlan vlan-id
Example:Router(config)# no mac-address-table secure address 0100.5e05.0505 vlan vlan 1
Enters the secure MAC address, its associated port, and the VLAN ID to be removed.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Command Purpose
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DETAILED STEPS
Follow these steps to remove a static address.
SUMMARY STEPS
1. enable
2. configure terminal
3. no mac-address-table static hw-addr [interface] interface-id [vlan] vlan-id
4. end
DETAILED STEPS
:
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 mac-address-table static hw-addr [interface] interface-id [vlan] vlan-id
Example:Router(config)# mac-address-table static 0100.5e05.0505 interface 0/3/1 vlan vlan 1
Enters the static MAC address, the interface, and the VLAN ID of those ports.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Command Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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You can remove all secure addresses by using the clear mac-address-table static command in privileged EXEC mode.
Verifying Static Addresses
Use the show mac-address-table static command to verify configuration:
Router # show mac-address-table static
Static Address TableDestination Address Address Type VLAN Destination Port------------------- ------------ ---- --------------------000a.000b.000c Static 1 FastEthernet0/1/0
Clearing All MAC Address Tables
To remove all addresses, use the clear mac-address command in privileged EXEC mode:
Configuration Examples for EtherSwitch HWICsThis section provides the following configuration examples:
• Range of Interface: Examples, page 186
• Optional Interface Feature: Examples, page 186
• Stacking: Example, page 187
• VLAN Configuration: Example, page 187
• VLAN Trunking Using VTP: Example, page 187
• Spanning Tree: Examples, page 188
• MAC Table Manipulation: Example, page 191
• Switched Port Analyzer (SPAN) Source: Examples, page 191
• IGMP Snooping: Example, page 191
Step 3 no mac-address-table static hw-addr [interface] interface-id [vlan] vlan-id
Example:Router(config)# no mac-address-table static 0100.5e05.0505 interface 0/3/1 vlan vlan
Enters the static MAC address, the interface, and the VLAN ID of the port to be removed.
Step 4 end
Example:Router(config)# end
Returns to privileged EXEC mode.
Command Purpose
Command Purpose
Router# clear mac-address-table Enters to clear all MAC address tables.
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• Storm-Control: Example, page 193
• Ethernet Switching: Examples, page 193
Range of Interface: Examples• Single Range Configuration: Example, page 186
• Range Macro Definition: Example, page 186
Single Range Configuration: Example
The following example shows all Fast Ethernet interfaces on an HWIC-4ESW in slot 2 being reenabled:
Router(config)# interface range fastEthernet 0/3/0 - 8Router(config-if-range)# no shutdownRouter(config-if-range)#*Mar 21 14:01:21.474: %LINK-3-UPDOWN: Interface FastEthernet0/3/0, changed state to up*Mar 21 14:01:21.490: %LINK-3-UPDOWN: Interface FastEthernet0/3/1, changed state to up*Mar 21 14:01:21.502: %LINK-3-UPDOWN: Interface FastEthernet0/3/2, changed state to up*Mar 21 14:01:21.518: %LINK-3-UPDOWN: Interface FastEthernet0/3/3, changed state to up*Mar 21 14:01:21.534: %LINK-3-UPDOWN: Interface FastEthernet0/3/4, changed state to up*Mar 21 14:01:21.546: %LINK-3-UPDOWN: Interface FastEthernet0/3/5, changed state to up*Mar 21 14:01:21.562: %LINK-3-UPDOWN: Interface FastEthernet0/3/6, changed state to up*Mar 21 14:01:21.574: %LINK-3-UPDOWN: Interface FastEthernet0/3/7, changed state to up*Mar 21 14:01:21.590: %LINK-3-UPDOWN: Interface FastEthernet0/3/8, changed state to upRouter(config-if-range)#
Range Macro Definition: Example
The following example shows an interface-range macro named enet_list being defined to select Fast Ethernet interfaces 0/1/0 through 0/1/3:
Router(config)# define interface-range enet_list fastethernet 0/1/0 - 0/1/3Router(config)#
The following example shows how to change to the interface-range configuration mode using the interface-range macro enet_list:
Router(config)# interface range macro enet_list
Optional Interface Feature: Examples• Interface Speed: Example, page 186
• Setting the Interface Duplex Mode: Example, page 187
• Adding a Description for an Interface: Example, page 187
Interface Speed: Example
The following example shows the interface speed being set to 100 Mbps on Fast Ethernet interface 0/3/7:
Router(config)# interface fastethernet 0/3/7Router(config-if)# speed 100
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Setting the Interface Duplex Mode: Example
The following example shows the interface duplex mode being set to full on Fast Ethernet interface 0/3/7:
Router(config)# interface fastethernet 0/3/7Router(config-if)# duplex full
Adding a Description for an Interface: Example
The following example shows how to add a description of Fast Ethernet interface 0/3/7:
Router(config)# interface fastethernet 0/3/7Router(config-if)# description Link to root switch
Stacking: ExampleThe following example shows how to stack two HWICs.
Router(config)# interface FastEthernet 0/1/8Router(config-if)# no shutdownRouter(config-if)# switchport stacking-partner interface FastEthernet 0/3/8Router(config-if)# interface FastEthernet 0/3/8Router(config-if)# no shutdown
Note In practice, the command switchport stacking-partner interface FastEthernet 0/partner-slot/partner-port needs to be executed for only one of the stacked ports. The other port will be automatically configured as a stacking port by the Cisco IOS software. The command no shutdown, however, must be executed for both of the stacked ports.
VLAN Configuration: ExampleThe following example shows how to configure inter-VLAN routing:
Router# vlan databaseRouter(vlan)# vlan 1Router(vlan)# vlan 2Router(vlan)# exitRouter# configure terminalRouter(config)# interface vlan 1Router(config-if)# ip address 10.1.1.1 255.255.255.0Router(config-if)# no shutRouter(config-if)# interface vlan 2Roouter(config-if)# ip address 10.2.2.2 255.255.255.0Router(config-if)# no shutRouter(config-if)# interface FastEthernet 0/1/0Router(config-if)# switchport access vlan 1Router(config-if)# interface Fast Ethernet 0/1/1Router(config-if)# switchport access vlan 2Router(config-if)# exit
VLAN Trunking Using VTP: ExampleThe following example shows how to configure the switch as a VTP server:
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Router# vlan databaseRouter(vlan)# vtp serverSetting device to VTP SERVER mode.Router(vlan)# vtp domain Lab_NetworkSetting VTP domain name to Lab_NetworkRouter(vlan)# vtp password WATERSetting device VLAN database password to WATER.Router(vlan)# exitAPPLY completed.Exiting....Router#
The following example shows how to configure the switch as a VTP client:
Router# vlan databaseRouter(vlan)# vtp clientSetting device to VTP CLIENT mode.Router(vlan)# exit
In CLIENT state, no apply attempted.Exiting....Router#
The following example shows how to configure the switch as VTP transparent:
Router# vlan databaseRouter(vlan)# vtp transparentSetting device to VTP TRANSPARENT mode.Router(vlan)# exitAPPLY completed.Exiting....Router#
Spanning Tree: Examples• Spanning-Tree Interface and Spanning-Tree Port Priority: Example, page 188
• Spanning-Tree Port Cost: Example, page 189
• Bridge Priority of a VLAN: Example, page 190
• Hello Time: Example, page 190
• Forward-Delay Time for a VLAN: Example, page 190
• Maximum Aging Time for a VLAN: Example, page 190
• Spanning Tree: Examples, page 190
• Spanning Tree Root: Example, page 191
Spanning-Tree Interface and Spanning-Tree Port Priority: Example
The following example shows the VLAN port priority of an interface being configured:
Router# configure terminal Router(config)# interface fastethernet 0/3/2Router(config-if)# spanning-tree vlan 20 port-priority 64 Router(config-if)# end Router#
The following example shows how to verify the configuration of VLAN 200 on the interface when it is configured as a trunk port:
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Router# show spanning-tree vlan 20
VLAN20 is executing the ieee compatible Spanning Tree protocol Bridge Identifier has priority 32768, address 00ff.ff90.3f54 Configured hello time 2, max age 20, forward delay 15 Current root has priority 32768, address 00ff.ff10.37b7 Root port is 33 (FastEthernet0/3/2), cost of root path is 19 Topology change flag not set, detected flag not set Number of topology flags 0 last change occurred 00:05:50 ago Times: hold 1, topology change 35, notification 2 hello 2, max age 20, forward delay 15 Timers: hello 0, topology change 0, notification 0, aging 0
Port 33 (FastEthernet0/3/2) of VLAN20 is forwarding Port path cost 18, Port priority 64, Port Identifier 64.33 Designated root has priority 32768, address 00ff.ff10.37b7 Designated bridge has priority 32768, address 00ff.ff10.37b7 Designated port id is 128.13, designated path cost 0 Timers: message age 2, forward delay 0, hold 0 Number of transitions to forwarding state: 1 BPDU: sent 1, received 175Router#
Spanning-Tree Port Cost: Example
The following example shows how to change the spanning-tree port cost of a Fast Ethernet interface:
Router# configure terminal Router(config)# interface fastethernet 0/3/2Router(config-if)# spanning-tree cost 18 Router(config-if)# end Router#
Router# show run interface fastethernet0/3/2Building configuration...
Current configuration: 140 bytes!interface FastEthernet0/3/2 switchport access vlan 20 no ip address spanning-tree vlan 20 port-priorityy 64 spanning-tree cost 18end
The following example shows how to verify the configuration of the interface when it is configured as an access port:
Router# show spanning-tree interface fastethernet 0/3/2 Port 33 (FastEthernet0/3/2) of VLAN20 is forwarding Port path cost 18, Port priority 64, Port Identifier 64.33 Designated root has priority 32768, address 00ff.ff10.37b7 Designated bridge has priority 32768, address 00ff.ff10.37b7 Designated port id is 128.13, designated path cost 0 Timers: message age 2, forward delay 0, hold 0 Number of transitions to forwarding state: 1 BPDU: sent 1, received 175Router#
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Bridge Priority of a VLAN: Example
The following example shows the bridge priority of VLAN 20 being configured to 33792:
Router# configure terminal Router(config)# spanning-tree vlan 20 priority 33792 Router(config)# end Router#
Hello Time: Example
The following example shows the hello time for VLAN 20 being configured to 7 seconds:
Router# configure terminal Router(config)# spanning-tree vlan 20 hello-time 7 Router(config)# end Router#
Forward-Delay Time for a VLAN: Example
The following example shows the forward delay time for VLAN 20 being configured to 21 seconds:
Router# configure terminal Router(config)# spanning-tree vlan 20 forward-time 21 Router(config)# end Router#
Maximum Aging Time for a VLAN: Example
The following example configures the maximum aging time for VLAN 20 to 36 seconds:
Router# configure terminal Router(config)# spanning-tree vlan 20 max-age 36 Router(config)# end Router#
Spanning Tree: Examples
The following example shows spanning tree being enabled on VLAN 20:
Router# configure terminal Router(config)# spanning-tree vlan 20 Router(config)# end Router#
Note Because spanning tree is enabled by default, issuing a show running command to view the resulting configuration will not display the command you entered to enable spanning tree.
The following example shows spanning tree being disabled on VLAN 20:
Router# configure terminal Router(config)# no spanning-tree vlan 20 Router(config)# end Router#
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Spanning Tree Root: Example
The following example shows the switch being configured as the root bridge for VLAN 10, with a network diameter of 4:
Router# configure terminal Router(config)# spanning-tree vlan 10 root primary diameter 4 Router(config)# exit Router#
MAC Table Manipulation: ExampleThe following example shows a static entry being configured in the MAC address table:
Router(config)# mac-address-table static beef.beef.beef int fa0/1/5Router(config)# end
The following example shows port security being configured in the MAC address table.
Router(config)# mac-address-table secure 0000.1111.2222 fa0/1/2 vlan 3Router(config)# end
Switched Port Analyzer (SPAN) Source: Examples• SPAN Source Configuration: Example, page 191
• SPAN Destination Configuration: Example, page 191
• Removing Sources or Destinations from a SPAN Session: Example, page 191
SPAN Source Configuration: Example
The following example shows SPAN session 1 being configured to monitor bidirectional traffic from source interface Fast Ethernet 0/1/1:
Router(config)# monitor session 1 source interface fastethernet 0/1/1
SPAN Destination Configuration: Example
The following example shows interface Fast Ethernet 0/3/7 being configured as the destination for SPAN session 1:
Router(config)# monitor session 1 destination interface fastethernet 0/3/7
Removing Sources or Destinations from a SPAN Session: Example
This following example shows interface Fast Ethernet 0/3/2 being removed as a SPAN source for SPAN session 1:
Router(config)# no monitor session 1 source interface fastethernet 0/3/2
IGMP Snooping: ExampleThe following example shows the output from configuring IGMP snooping:
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Router# show mac-address-table multicast igmp-snooping
HWIC Slot: 1 -------------- MACADDR VLANID INTERFACES
0100.5e05.0505 1 Fa0/1/10100.5e06.0606 2
HWIC Slot: 3 -------------- MACADDR VLANID INTERFACES
0100.5e05.0505 1 Fa0/3/40100.5e06.0606 2 Fa0/3/0
Router#
The following is an example of output from the show running interface privileged EXEC command for VLAN 1:
Router# show running interface vlan 1
Building configuration...
Current configuration :82 bytes ! interface Vlan1 ip address 192.168.4.90 255.255.255.0 ip pim sparse-mode end
Router# show running interface vlan 2
Building configuration...
Current configuration :82 bytes ! interface Vlan2 ip address 192.168.5.90 255.255.255.0 ip pim sparse-mode end
Router# Router# show ip igmp group
IGMP Connected Group Membership Group Address Interface Uptime Expires Last Reporter 209.165.200.225 Vlan1 01:06:40 00:02:20 192.168.41.101 209.165.200.226 Vlan2 01:07:50 00:02:17 192.168.5.90 209.165.200.227 Vlan1 01:06:37 00:02:25 192.168.41.100 209.165.200.228 Vlan2 01:07:40 00:02:21 192.168.31.100 209.165.200.229 Vlan1 01:06:36 00:02:22 192.168.41.101 209.165.200.230 Vlan2 01:06:39 00:02:20 192.168.31.101 Router#
Router# show ip mroute
IP Multicast Routing Table Flags:D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected, L - Local, P - Pruned, R - RP-bit set, F - Register flag, T - SPT-bit set, J - Join SPT, M - MSDP created entry, X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
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U - URD, I - Received Source Specific Host Report Outgoing interface flags:H - Hardware switched Timers:Uptime/Expires Interface state:Interface, Next-Hop or VCD, State/Mode
(*, 209.165.200.230), 01:06:43/00:02:17, RP 0.0.0.0, flags:DC Incoming interface:Null, RPF nbr 0.0.0.0 Outgoing interface list: Vlan1, Forward/Sparse, 01:06:43/00:02:17
(*, 209.165.200.226), 01:12:42/00:00:00, RP 0.0.0.0, flags:DCL Incoming interface:Null, RPF nbr 0.0.0.0 Outgoing interface list: Vlan2, Forward/Sparse, 01:07:53/00:02:14
(*, 209.165.200.227), 01:07:43/00:02:22, RP 0.0.0.0, flags:DC Incoming interface:Null, RPF nbr 0.0.0.0 Outgoing interface list: Vlan1, Forward/Sparse, 01:06:40/00:02:22 Vlan2, Forward/Sparse, 01:07:44/00:02:17
(*, 209.165.200.2282), 01:06:43/00:02:18, RP 0.0.0.0, flags:DC Incoming interface:Null, RPF nbr 0.0.0.0 Outgoing interface list: Vlan1, Forward/Sparse, 01:06:40/00:02:18 Vlan2, Forward/Sparse, 01:06:43/00:02:16
Router#
Storm-Control: ExampleThe following example shows bandwidth-based multicast suppression being enabled at 70 percent on Fast Ethernet interface 2:
Router# configure terminalRouter(config)# interface FastEthernet0/3/3Router(config-if)# storm-control multicast threshold 70.0 30.0Router(config-if)# end
Router# show storm-control multicastInterface Filter State Upper Lower Current--------- ------------ ----- ----- -------Fa0/1/0 inactive 100.00% 100.00% N/AFa0/1/1 inactive 100.00% 100.00% N/AFa0/1/2 inactive 100.00% 100.00% N/AFa0/1/3 inactive 100.00% 100.00% N/AFa0/3/0 inactive 100.00% 100.00% N/AFa0/3/1 inactive 100.00% 100.00% N/AFa0/3/2 inactive 100.00% 100.00% N/AFa0/3/3 Forwarding 70.00% 30.00% 0.00%Fa0/3/4 inactive 100.00% 100.00% N/AFa0/3/5 inactive 100.00% 100.00% N/AFa0/3/6 inactive 100.00% 100.00% N/AFa0/3/7 inactive 100.00% 100.00% N/AFa0/3/8 inactive 100.00% 100.00% N/A
Ethernet Switching: Examples• Subnets for Voice and Data: Example, page 194
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• Inter-VLAN Routing: Example, page 194
• Single Subnet Configuration: Example, page 195
• Ethernet Ports on IP Phones with Multiple Ports: Example, page 195
Subnets for Voice and Data: Example
The following example shows separate subnets being configured for voice and data on the EtherSwitch HWIC:
interface FastEthernet0/1/1description DOT1Q port to IP Phoneswitchport native vlan 50switchport mode trunkswitchport voice vlan 150
interface Vlan 150description voice vlanip address 209.165.200.227 255.255.255.0ip helper-address 209.165.200.228 (See Note below)
interface Vlan 50description data vlanip address 209.165.200.220 255.255.255.0
This configuration instructs the IP phone to generate a packet with an 802.1Q VLAN ID of 150 with an 802.1p value of 5 (default for voice bearer traffic).
Note In a centralized CallManager deployment model, the DHCP server might be located across the WAN link. If so, an ip helper-address command pointing to the DHCP server should be included on the voice VLAN interface for the IP phone. This is done to obtain its IP address as well as the address of the TFTP server required for its configuration.
Be aware that IOS supports a DHCP server function. If this function is used, the EtherSwitch HWIC serves as a local DHCP server and a helper address would not be required.
Inter-VLAN Routing: Example
Configuring inter-VLAN routing is identical to the configuration on an EtherSwitch HWIC with an MSFC. Configuring an interface for WAN routing is consistent with other IOS platforms.
The following example provides a sample configuration:
interface Vlan 160description voice vlanip address 10.6.1.1 255.255.255.0
interface Vlan 60description data vlanip address 10.60.1.1 255.255.255.0
interface Serial0/3/0ip address 172.3.1.2 255.255.255.0
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Note Standard IGP routing protocols such as RIP, IGRP, EIGRP, and OSPF are supported on the EtherSwitch HWIC. Multicast routing is also supported for PIM dense mode, sparse mode and sparse-dense mode.
Single Subnet Configuration: Example
The EtherSwitch HWIC supports the use of an 802.1p-only option when configuring the voice VLAN. Using this option allows the IP phone to tag VoIP packets with a Cost of Service of 5 on the native VLAN, while all PC data traffic is sent untagged.
The following example shows a single subnet configuration for the EtherSwitch HWIC:
Router# FastEthernet 0/1/2description Port to IP Phone in single subnetswitchport access vlan 40
The EtherSwitch HWIC instructs the IP phone to generate an 802.1Q frame with a null VLAN ID value but with an 802.1p value (default is COS of 5 for bearer traffic). The voice and data VLANs are both 40 in this example.
Ethernet Ports on IP Phones with Multiple Ports: Example
The following example illustrates the configuration for the IP phone:
interface FastEthernet0/x/xswitchport voice vlan xswitchport mode trunk
The following example illustrates the configuration for the PC:
interface FastEthernet0/x/yswitchport mode accessswitchport access vlan y
Note Using a separate subnet, and possibly a separate IP address space, may not be an option for some small branch offices due to the IP routing configuration. If the IP routing can handle an additional subnet at the remote branch, you can use Cisco Network Registrar and secondary addressing.
Additional ReferencesThe following sections provide references related to EtherSwitch HWICs.
Related Documents
Related Topic Document Title
Hardware Installation of Interface Cards Cisco Interface Cards Installation Guide
Cisco HWIC-4ESW and HWIC-D-9ESW EtherSwitch Interface CardsAdditional References
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Standards
MIBs
RFCs
Technical Assistance
Information about configuring Voice over IP features Cisco IOS Voice, Video, and Fax Configuration Guide
Voice over IP commands Cisco IOS Voice, Video, and Fax Command Reference, Release 12.3 T
Standards Title
No new or modified standards are supported by this feature, and support for existing standards have not been modified by this feature.
—
MIBs MIBs Link
No new or modified MIBs are supported by this feature, and support for existing MIBs have not been modified by this feature.
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
http://www.cisco.com/go/mibs
RFCs Title
No new or modified RFCs are supported by this feature, and support for existing RFCs have not been modified by this feature.
—
Description Link
Technical Assistance Center (TAC) home page, containing 30,000 pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.
http://www.cisco.com/public/support/tac/home.shtml
Related Topic Document Title
Cisco HWIC-4ESW and HWIC-D-9ESW EtherSwitch Interface CardsCommand Reference
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Command ReferenceThis feature uses no new or modified commands. To see the command pages for the commands used with this feature, go to the Cisco IOS Master Commands List, Release 12.4, at http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124mindx/124index.htm.
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Feature Information for the Cisco HWIC-4ESW and the Cisco HWIC-D-9ESW EtherSwitch Cards
Table 10 lists the features in this module and provides links to specific configuration information. Only features that were introduced or modified in 12.3(8)T4 or a later release appear in the table.
Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.
Cisco IOS software images are specific to a Cisco IOS software release, a feature set, and a platform. Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Note Table 10 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.
Table 10 Feature Information for the 4-Port Cisco HWIC-4ESW and the 9-Port Cisco HWIC-D-9ESW EtherSwitch High
Speed WAN Interface Cards
Feature Name Releases Feature Information
4-port Cisco HWIC-4ESW and the 9-port Cisco HWIC-D-9ESW EtherSwitch high speed WAN interface cards (HWICs) hardware feature
12.3(8)T4 The 4-port Cisco HWIC-4ESW and the 9-port Cisco HWIC-D-9ESW EtherSwitch high speed WAN interface cards (HWICs) hardware feature is supported on Cisco 1800 (modular), Cisco 2800, and Cisco 3800 series integrated services routers.
Cisco EtherSwitch HWICs are 10/100BASE-T Layer 2 Ethernet switches with Layer 3 routing capability. (Layer 3 routing is forwarded to the host and is not actually performed at the switch.) Traffic between different VLANs on a switch is routed through the router platform. Any one port on a Cisco EtherSwitch HWIC may be configured as a stacking port to link to another Cisco EtherSwitch HWIC or EtherSwitch network module in the same system. An optional power module can also be added to provide inline power for IP telephones. The HWIC-D-9ESW HWIC requires a double-wide card slot.
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EtherSwitch Network Module
First Published: May 17, 2005Last Updated: April 15, 2006
This document explains how to configure the EtherSwitch network module. This network module is supported on Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers. The EtherSwitch network module is a modular, high-density voice network module that provides Layer 2 switching across Ethernet ports. The EtherSwitch network module has sixteen 10/100 switched Ethernet ports with integrated inline power and QoS features that are designed to extend Cisco AVVID-based voice-over-IP (VoIP) networks to small branch offices.
Feature History for the EtherSwitch Module Feature
Finding Support Information for Platforms and Cisco IOS Software Images
Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.
Contents• Prerequisites for the EtherSwitch Network Module, page 200
• Restrictions for the EtherSwitch Network Module, page 200
• Information About the EtherSwitch Network Module, page 201
• How to Configure the EtherSwitch Network Module, page 241
Release Modification
12.2(2)XT This feature was introduced on the Cisco 2600 series, Cisco 3600 series, and Cisco 3700 series routers.
12.2(8)T This feature was integrated into Cisco IOS Release 12.2(8)T.
12.2(15)ZJ Added switching software enhancements: IEEE 802.1x, QoS (including Layer 2/Layer 3 CoS/DSCP mapping and rate limiting), security ACL, IGMP snooping, per-port storm control, and fallback bridging support for switch virtual interfaces (SVIs).
12.3(4)T The switching software enhancements from Cisco IOS Release 12.2(15)ZJ were integrated into Cisco IOS Release 12.3(4)T.
EtherSwitch Network ModulePrerequisites for the EtherSwitch Network Module
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• Configuration Examples for the EtherSwitch Network Module, page 324
• Additional References, page 349
• Command Reference, page 351
• Glossary, page 353
Prerequisites for the EtherSwitch Network Module• Cisco IOS Release 12.3 or later release
• Basic configuration of the Cisco 2600 series, Cisco 3600 series, or Cisco 3700 series router
In addition, complete the following tasks before configuring this feature:
• Configure IP routing
For more information on IP routing, refer to the Cisco IOS IP Configuration Guide.
• Set up the call agents
For more information on setting up call agents, refer to the documentation that accompanies the call agents used in your network configuration.
Restrictions for the EtherSwitch Network ModuleThe following functions are not supported by the EtherSwitch network module:
• CGMP client, CGMP fast-leave
• Dynamic ports
• Dynamic access ports
• Secure ports
• Dynamic trunk protocol
• Dynamic VLANs
• GARP, GMRP, and GVRP
• ISL tagging (The chip does not support ISL.)
• Layer 3 switching onboard
• Monitoring of VLANs
• Multi-VLAN ports Network Port
• Shared STP instances
• STP uplink fast for clusters
• VLAN-based SPAN
• VLAN Query Protocol
• VTP Pruning Protocol
• Web-based management interface
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Information About the EtherSwitch Network ModuleTo configure the EtherSwitch network module, you should understand the following concepts:
• EtherSwitch Network Module: Benefits, page 201
• Ethernet Switching in Cisco AVVID Architecture, page 202
• VLANs, page 202
• Inline Power for Cisco IP Phones, page 204
• Using the Spanning Tree Protocol with the EtherSwitch network module, page 204
• Layer 2 Ethernet Switching, page 216
• Cisco Discovery Protocol, page 218
• Port Security, page 218
• 802.1x Authentication, page 218
• Storm Control, page 222
• EtherChannel, page 224
• Flow Control on Gigabit Ethernet Ports, page 224
• Intrachassis Stacking, page 225
• Switched Port Analyzer, page 225
• Switched Virtual Interface, page 227
• Routed Ports, page 227
• IP Multicast Layer 3 Switching, page 227
• IGMP Snooping, page 228
• Fallback Bridging, page 230
• Network Security with ACLs at Layer 2, page 232
• Quality of Service for the EtherSwitch Network Module, page 235
EtherSwitch Network Module: Benefits• Statistical gains by combining multiple traffic types over a common IP infrastructure.
• Long distance savings
• Support for intra-chassis stacking
• Voice connectivity over data applications
• IPSec, ACL, VPN and Firewall options
• New broadband WAN options
The Interface Range Specification feature makes configuration easier for these reasons:
• Identical commands can be entered once for a range of interfaces, rather than being entered separately for each interface.
• Interface ranges can be saved as macros.
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Ethernet Switching in Cisco AVVID ArchitectureThe EtherSwitch network module is designed to work as part of the Cisco Architecture for Voice, Video, and Integrated Data (AVVID) solution. The EtherSwitch network module has sixteen 10/100 switched Ethernet ports with integrated inline power and QoS features that allow for extending Cisco AVVID-based voice-over-IP (VoIP) networks to small branch offices.
The 16-port EtherSwitch network module has sixteen 10/100BASE-TX ports and an optional 10/100/1000BASE-T Gigabit Ethernet port. The 36-port EtherSwitch network module has thirty six 10/100BASE-TX ports and two optional 10/100/1000BASE-T Gigabit Ethernet ports. The gigabit Ethernet can be used as an uplink port to a server or as a stacking link to another 16- or 36-port EtherSwitch network module in the same system. The 36-port EtherSwitch network module requires a double-wide slot. An optional power module can also be added to provide inline power for IP telephones.
As an access gateway switch, the EtherSwitch network module can be deployed as a component of a centralized call-processing network using a centrally deployed Cisco CallManager (CCM). Instead of deploying and managing key systems or PBXs in small branch offices, applications are centrally located at the corporate headquarters or data center and are accessed via the IP WAN.
By default, the EtherSwitch network module provides the following settings with respect to Cisco AVVID:
• All switch ports are in access VLAN 1.
• All switch ports are static access ports, not 802.1Q trunk ports.
• Default voice VLAN is not configured on the switch.
• Inline power is automatically supplied on the 10/100 ports.
VLANsVirtual local-area networks (VLANs) are a group of end stations with a common set of requirements, independent of physical location. VLANs have the same attributes as a physical LAN but allow you to group end stations even if they are not located physically on the same LAN segment.
VLAN Trunk Protocol
VLAN Trunk Protocol (VTP) is a Layer 2 messaging protocol that maintains VLAN configuration consistency by managing the addition, deletion, and renaming of VLANs within a VTP domain. A VTP domain (also called a VLAN management domain) is made up of one or more switches that share the same VTP domain name and that are interconnected with trunks. VTP minimizes misconfigurations and configuration inconsistencies that can result in a number of problems, such as duplicate VLAN names, incorrect VLAN-type specifications, and security violations. Before you create VLANs, you must decide whether to use VTP in your network. With VTP, you can make configuration changes centrally on one or more switches and have those changes automatically communicated to all the other switches in the network.
VTP Domain
A VTP domain (also called a VLAN management domain) is made up of one or more interconnected switches that share the same VTP domain name. A switch can be configured to be in only one VTP domain. You make global VLAN configuration changes for the domain using either the command-line interface (CLI) or Simple Network Management Protocol (SNMP).
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By default, the switch is in VTP server mode and is in an un-named domain state until the switch receives an advertisement for a domain over a trunk link or until you configure a management domain. You cannot create or modify VLANs on a VTP server until the management domain name is specified or learned.
If the switch receives a VTP advertisement over a trunk link, it inherits the management domain name and the VTP configuration revision number. The switch ignores advertisements with a different management domain name or an earlier configuration revision number.
If you configure the switch as VTP transparent, you can create and modify VLANs, but the changes affect only the individual switch.
When you make a change to the VLAN configuration on a VTP server, the change is propagated to all switches in the VTP domain. VTP advertisements are transmitted out all trunk connections using IEEE 802.1Q encapsulation.
VTP maps VLANs dynamically across multiple LAN types with unique names and internal index associations. Mapping eliminates excessive device administration required from network administrators.
VTP Modes
You can configure a switch to operate in any one of these VTP modes:
• Server—In VTP server mode, you can create, modify, and delete VLANs and specify other configuration parameters (such as VTP version) for the entire VTP domain. VTP servers advertise their VLAN configuration to other switches in the same VTP domain and synchronize their VLAN configuration with other switches based on advertisements received over trunk links. VTP server is the default mode.
• Client—VTP clients behave the same way as VTP servers, but you cannot create, change, or delete VLANs on a VTP client.
• Transparent—VTP transparent switches do not participate in VTP. A VTP transparent switch does not advertise its VLAN configuration and does not synchronize its VLAN configuration based on received advertisements. However, in VTP version 2, transparent switches do forward VTP advertisements that they receive out their trunk interfaces.
VTP Advertisements
Each switch in the VTP domain sends periodic advertisements out each trunk interface to a reserved multicast address. VTP advertisements are received by neighboring switches, which update their VTP and VLAN configurations as necessary.
The following global configuration information is distributed in VTP advertisements:
• VLAN IDs (801.Q)
• VTP domain name
• VTP configuration revision number
• VLAN configuration, including maximum transmission unit (MTU) size for each VLAN
• Frame format
VTP Version 2
If you use VTP in your network, you must decide whether to use VTP version 1 or version 2. VTP version 2 supports the following features not supported in version 1:
Unrecognized Type-Length-Value (TLV) Support—A VTP server or client propagates configuration changes to its other trunks, even for TLVs it is not able to parse. The unrecognized TLV is saved in NVRAM.
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Version-Dependent Transparent Mode—In VTP version 1, a VTP transparent switch inspects VTP messages for the domain name and version, and forwards a message only if the version and domain name match. Since only one domain is supported in the NM-16ESW software, VTP version 2 forwards VTP messages in transparent mode, without checking the version.
Consistency Checks—In VTP version 2, VLAN consistency checks (such as VLAN names and values) are performed only when you enter new information through the CLI or SNMP. Consistency checks are not performed when new information is obtained from a VTP message, or when information is read from NVRAM. If the digest on a received VTP message is correct, its information is accepted without consistency checks.
VTP Configuration Guidelines and Restrictions
Follow these guidelines and restrictions when implementing VTP in your network:
• All switches in a VTP domain must run the same VTP version.
• You must configure a password on each switch in the management domain when in secure mode.
• A VTP version 2-capable switch can operate in the same VTP domain as a switch running VTP version 1, provided that VTP version 2 is disabled on the VTP version 2-capable switch. (VTP version 2 is disabled by default).
• Do not enable VTP version 2 on a switch unless all switches in the same VTP domain are version 2-capable. When you enable VTP version 2 on a switch, all version 2-capable switches in the domain enable VTP version 2.
• The Cisco IOS end command and the Ctrl-Z keystrokes are not supported in VLAN database mode.
• The VLAN database stored on internal Flash is supported.
• Use the squeeze flash command to remove old copies of overwritten VLAN databases.
Inline Power for Cisco IP PhonesThe EtherSwitch network module can supply inline power to a Cisco 7960 IP phone, if required. The Cisco 7960 IP phone can also be connected to an AC power source and supply its own power to the voice circuit. When the Cisco 7960 IP phone is supplying its own power, a EtherSwitch network module can forward IP voice traffic to and from the phone.
A detection mechanism on the EtherSwitch network module determines whether it is connected to a Cisco 7960 IP phone. If the switch senses that there is no power on the circuit, the switch supplies the power. If there is power on the circuit, the switch does not supply it.
You can configure the switch to never supply power to the Cisco 7960 IP phone and to disable the detection mechanism.
Using the Spanning Tree Protocol with the EtherSwitch network moduleSpanning Tree Protocol (STP) is a Layer 2 link management protocol that provides path redundancy while preventing undesirable loops in the network. For a Layer 2 Ethernet network to function properly, only one active path can exist between any two stations. Spanning tree operation is transparent to end stations, which cannot detect whether they are connected to a single LAN segment or to a switched LAN of multiple segments.
The EtherSwitch network module uses STP (the IEEE 802.1D bridge protocol) on all VLANs. By default, a single instance of STP runs on each configured VLAN (provided that you do not manually disable STP). You can enable and disable STP on a per-VLAN basis.
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When you create fault-tolerant internetworks, you must have a loop-free path between all nodes in a network. The spanning tree algorithm calculates the best loop-free path throughout a switched Layer 2 network. Switches send and receive spanning tree frames at regular intervals. The switches do not forward these frames but use the frames to construct a loop-free path.
Multiple active paths between end stations cause loops in the network. If a loop exists in the network, end stations might receive duplicate messages and switches might learn endstation MAC addresses on multiple Layer 2 interfaces. These conditions result in an unstable network.
Spanning Tree Protocol (STP) defines a tree with a root switch and a loop-free path from the root to all switches in the Layer 2 network. STP forces redundant data paths into a standby (blocked) state. If a network segment in the spanning tree fails and a redundant path exists, the spanning tree algorithm recalculates the spanning tree topology and activates the standby path.
When two ports on a switch are part of a loop, the spanning tree port priority and port path cost setting determine which port is put in the forwarding state and which port is put in the blocking state. The spanning tree port priority value represents the location of an interface in the network topology and how well located it is to pass traffic. The spanning tree port path cost value represents media speed.
Bridge Protocol Data Units
The stable active spanning tree topology of a switched network is determined by the following:
• The unique bridge ID (bridge priority and MAC address) associated with each VLAN on each switch
• The spanning tree path cost to the root bridge
• The port identifier (port priority and MAC address) associated with each Layer 2 interface
The Bridge Protocol Data Units (BPDU) are transmitted in one direction from the root switch, and each switch sends configuration BPDUs to communicate and compute the spanning tree topology. Each configuration BPDU contains the following minimal information:
• The unique bridge ID of the switch that the transmitting switch believes to be the root switch
• The spanning tree path cost to the root
• The bridge ID of the transmitting bridge
• Message age
• The identifier of the transmitting port
• Values for the hello, forward delay, and max-age protocol timers
When a switch transmits a BPDU frame, all switches connected to the LAN on which the frame is transmitted receive the BPDU. When a switch receives a BPDU, it does not forward the frame but instead uses the information in the frame to calculate a BPDU, and, if the topology changes, initiate a BPDU transmission.
A BPDU exchange results in the following:
• One switch is elected as the root switch.
• The shortest distance to the root switch is calculated for each switch based on the path cost.
• A designated bridge for each LAN segment is selected. This is the switch closest to the root bridge through which frames are forwarded to the root.
• A root port is selected. This is the port providing the best path from the bridge to the root bridge.
• Ports included in the spanning tree are selected.
• The Root Bridge is elected.
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For each VLAN, the switch with the highest bridge priority (the lowest numerical priority value) is elected as the root switch. If all switches are configured with the default priority (32768), the switch with the lowest MAC address in the VLAN becomes the root switch.
The spanning tree root switch is the logical center of the spanning tree topology in a switched network. All paths that are not needed to reach the root switch from anywhere in the switched network are placed in spanning tree blocking mode.
BPDUs contain information about the transmitting bridge and its ports, including bridge and MAC addresses, bridge priority, port priority, and path cost. Spanning tree uses this information to elect the root bridge and root port for the switched network, as well as the root port and designated port for each switched segment.
STP Timers
Table 11 describes the STP timers that affect the entire spanning tree performance.
Table 11 STP Timers
Spanning Tree Port States
Propagation delays can occur when protocol information passes through a switched LAN. As a result, topology changes can take place at different times and at different places in a switched network. When a Layer 2 interface changes directly from nonparticipation in the spanning tree topology to the forwarding state, it can create temporary data loops. Ports must wait for new topology information to propagate through the switched LAN before starting to forward frames. They must allow the frame lifetime to expire for frames that have been forwarded using the old topology.
Each Layer 2 interface on a switch using spanning tree exists in one of the following five states:
• Blocking—The Layer 2 interface does not participate in frame forwarding.
• Listening—First transitional state after the blocking state when spanning tree determines that the Layer 2 interface should participate in frame forwarding.
• Learning—The Layer 2 interface prepares to participate in frame forwarding.
• Forwarding—The Layer 2 interface forwards frames.
• Disabled—The Layer 2 interface does not participate in spanning tree and is not forwarding frames.
A Layer 2 interface moves through these five states as follows:
• From initialization to blocking
• From blocking to listening or to disabled
• From listening to learning or to disabled
• From learning to forwarding or to disabled
• From forwarding to disabled
Timer Purpose
Hello timer Determines how often the switch broadcasts hello messages to other switches.
Forward delay timer Determines how long each of the listening and learning states will last before the port begins forwarding.
Maximum age timer Determines the amount of time protocol information received on a port is stored by the switch.
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Figure 20 illustrates how a port moves through the five stages.
Figure 20 STP Port States
Boot-up Initialization
When you enable spanning tree, every port in the switch, VLAN, or network goes through the blocking state and the transitory states of listening and learning at power up. If properly configured, each Layer 2 interface stabilizes to the forwarding or blocking state.
When the spanning tree algorithm places a Layer 2 interface in the forwarding state, the following process occurs:
1. The Layer 2 interface is put into the listening state while it waits for protocol information that suggests that it should go to the blocking state.
2. The Layer 2 interface waits for the forward delay timer to expire, moves the Layer 2 interface to the learning state, and resets the forward delay timer.
3. In the learning state, the Layer 2 interface continues to block frame forwarding as it learns end station location information for the forwarding database.
4. The Layer 2 interface waits for the forward delay timer to expire and then moves the Layer 2 interface to the forwarding state, where both learning and frame forwarding are enabled.
Blocking State
A Layer 2 interface in the blocking state does not participate in frame forwarding, as shown in Figure 21. After initialization, a BPDU is sent out to each Layer 2 interface in the switch. A switch initially assumes it is the root until it exchanges BPDUs with other switches. This exchange establishes which switch in the network is the root or root bridge. If only one switch is in the network, no exchange occurs, the forward delay timer expires, and the ports move to the listening state. A port always enters the blocking state following switch initialization.
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Figure 21 Interface 2 in Blocking State
A Layer 2 interface in the blocking state performs as follows:
• Discards frames received from the attached segment.
• Discards frames switched from another interface for forwarding.
• Does not incorporate end station location into its address database. (There is no learning on a blocking Layer 2 interface, so there is no address database update.)
• Receives BPDUs and directs them to the system module.
• Does not transmit BPDUs received from the system module.
• Receives and responds to network management messages.
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Listening State
The listening state is the first transitional state a Layer 2 interface enters after the blocking state. The Layer 2 interface enters this state when STP determines that the Layer 2 interface should participate in frame forwarding. Figure 22 shows a Layer 2 interface in the listening state.
Figure 22 Interface 2 in Listening State
A Layer 2 interface in the listening state performs as follows:
• Discards frames received from the attached segment.
• Discards frames switched from another interface for forwarding.
• Does not incorporate end station location into its address database. (There is no learning at this point, so there is no address database update.)
• Receives BPDUs and directs them to the system module.
• Receives, processes, and transmits BPDUs received from the system module.
• Receives and responds to network management messages.
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Learning State
A Layer 2 interface in the learning state prepares to participate in frame forwarding. The Layer 2 interface enters the learning state from the listening state. Figure 23 shows a Layer 2 interface in the learning state.
Figure 23 Interface 2 in Learning State
A Layer 2 interface in the learning state performs as follows:
• Discards frames received from the attached segment.
• Discards frames switched from another interface for forwarding.
• Incorporates end station location into its address database.
• Receives BPDUs and directs them to the system module.
• Receives, processes, and transmits BPDUs received from the system module.
• Receives and responds to network management messages.
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Forwarding State
A Layer 2 interface in the forwarding state forwards frames, as shown in Figure 24. The Layer 2 interface enters the forwarding state from the learning state.
Figure 24 Interface 2 in Forwarding State
A Layer 2 interface in the forwarding state performs as follows:
• Forwards frames received from the attached segment.
• Forwards frames switched from another Layer 2 interface for forwarding.
• Incorporates end station location information into its address database.
• Receives BPDUs and directs them to the system module.
• Processes BPDUs received from the system module.
• Receives and responds to network management messages.
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Disabled State
A Layer 2 interface in the disabled state does not participate in frame forwarding or spanning tree, as shown in Figure 25. A Layer 2 interface in the disabled state is virtually nonoperational.
Figure 25 Interface 2 in Disabled State
A disabled Layer 2 interface performs as follows:
• Discards frames received from the attached segment.
• Discards frames switched from another Layer 2 interface for forwarding.
• Does not incorporate end station location into its address database. (There is no learning, so there is no address database update.)
• Does not receive BPDUs.
• Does not receive BPDUs for transmission from the system module.
MAC Address Allocation
The MAC address allocation manager has a pool of MAC addresses that are used as the bridge IDs for the VLAN spanning trees. In Table 12 you can view the number of VLANs allowed for each platform.
Filteringdatabase
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Table 12 Number of VLANs Allowed by Platform
Platform Maximum Number of VLANs Allowed
Cisco 3640 or higher 64 VLANs
Cisco 2600 32 VLANs
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MAC addresses are allocated sequentially, with the first MAC address in the range assigned to VLAN 1, the second MAC address in the range assigned to VLAN 2, and so forth.
For example, if the MAC address range is 00-e0-1e-9b-2e-00 to 00-e0-1e-9b-31-ff, the VLAN 1 bridge ID is 00-e0-1e-9b-2e-00, the VLAN 2 bridge ID is 00-e0-1e-9b-2e-01, the VLAN 3 bridge ID is 00-e0-1e-9b-2e-02, and so forth.
Default Spanning Tree Configuration
Table 13 shows the default Spanning Tree configuration values.
Spanning Tree Port Priority
In the event of a loop, spanning tree considers port priority when selecting an interface to put into the forwarding state. You can assign higher priority values to interfaces that you want spanning tree to select first, and lower priority values to interfaces that you want spanning tree to select last. If all interfaces have the same priority value, spanning tree puts the interface with the lowest interface number in the forwarding state and blocks other interfaces. The possible priority range is 0 to 255, configurable in increments of 4 (the default is 128).
Cisco IOS software uses the port priority value when the interface is configured as an access port and uses VLAN port priority values when the interface is configured as a trunk port.
Spanning Tree Port Cost
The spanning tree port path cost default value is derived from the media speed of an interface. In the event of a loop, spanning tree considers port cost when selecting an interface to put into the forwarding state. You can assign lower cost values to interfaces that you want spanning tree to select first and higher
Table 13 Spanning Tree Default Configuration
Feature Default Value
Enable state Spanning tree enabled for all VLANs
Bridge priority 32768
Spanning tree port priority (configurable on a per-interface basis; used on interfaces configured as Layer 2 access ports)
128
Spanning tree port cost (configurable on a per-interface basis; used on interfaces configured as Layer 2 access ports)
Fast Ethernet: 19
Ethernet: 100
Gigabit Ethernet: 19 when operated in 100-Mb mode, and 4 when operated in 1000-Mb mode
Spanning tree VLAN port priority (configurable on a per-VLAN basis; used on interfaces configured as Layer 2 trunk ports)
128
Spanning tree VLAN port cost (configurable on a per-VLAN basis; used on interfaces configured as Layer 2 trunk ports)
Fast Ethernet: 10
Ethernet: 10
Hello time 2 seconds
Forward delay time 15 seconds
Maximum aging time 20 seconds
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cost values to interfaces that you want spanning tree to select last. If all interfaces have the same cost value, spanning tree puts the interface with the lowest interface number in the forwarding state and blocks other interfaces.
The possible cost range is 0 to 65535 (the default is media-specific).
Spanning tree uses the port cost value when the interface is configured as an access port and uses VLAN port cost values when the interface is configured as a trunk port.
BackboneFast
BackboneFast is initiated when a root port or blocked port on a switch receives inferior BPDUs from its designated bridge. An inferior BPDU identifies one switch as both the root bridge and the designated bridge. When a switch receives an inferior BPDU, it means that a link to which the switch is not directly connected (an indirect link) has failed (that is, the designated bridge has lost its connection to the root switch). Under STP rules, the switch ignores inferior BPDUs for the configured maximum aging time specified by the spanning-tree max-age global configuration command.
The switch tries to determine if it has an alternate path to the root switch. If the inferior BPDU arrives on a blocked port, the root port and other blocked ports on the switch become alternate paths to the root switch. (Self-looped ports are not considered alternate paths to the root switch.) If the inferior BPDU arrives on the root port, all blocked ports become alternate paths to the root switch. If the inferior BPDU arrives on the root port and there are no blocked ports, the switch assumes that it has lost connectivity to the root switch, causes the maximum aging time on the root to expire, and becomes the root switch according to normal STP rules.
If the switch has alternate paths to the root switch, it uses these alternate paths to transmit a new kind of Protocol Data Unit (PDU) called the Root Link Query PDU. The switch sends the Root Link Query PDU on all alternate paths to the root switch. If the switch determines that it still has an alternate path to the root, it causes the maximum aging time on the ports on which it received the inferior BPDU to expire. If all the alternate paths to the root switch indicate that the switch has lost connectivity to the root switch, the switch causes the maximum aging times on the ports on which it received an inferior BPDU to expire. If one or more alternate paths can still connect to the root switch, the switch makes all ports on which it received an inferior BPDU its designated ports and moves them out of the blocking state (if they were in the blocking state), through the listening and learning states, and into the forwarding state.
Figure 26 shows an example topology with no link failures. Switch A, the root switch, connects directly to Switch B over link L1 and to Switch C over link L2. The interface on Switch C that connects directly to Switch B is in the blocking state.
Figure 26 BackboneFast Example Before Indirect Link Failure
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If link L1 fails, Switch C cannot detect this failure because it is not connected directly to link L1. However, because Switch B is directly connected to the root switch over L1, it detects the failure, elects itself the root, and begins sending BPDUs to Switch C, identifying itself as the root. When Switch C receives the inferior BPDUs from Switch B, Switch C assumes that an indirect failure has occurred. At that point, BackboneFast allows the blocked port on Switch C to move immediately to the listening state without waiting for the maximum aging time for the port to expire. BackboneFast then changes the interface on Switch C to the forwarding state, providing a path from Switch B to Switch A. This switchover takes approximately 30 seconds, twice the Forward Delay time if the default Forward Delay time of 15 seconds is set. Figure 27 shows how BackboneFast reconfigures the topology to account for the failure of link L1.
Figure 27 BackboneFast Example After Indirect Link Failure
If a new switch is introduced into a shared-medium topology as shown in Figure 28, BackboneFast is not activated because the inferior BPDUs did not come from the recognized designated bridge (Switch B). The new switch begins sending inferior BPDUs that say it is the root switch. However, the other switches ignore these inferior BPDUs, and the new switch learns that Switch B is the designated bridge to Switch A, the root switch.
Figure 28 Adding a Switch in a Shared-Medium Topology
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Layer 2 Ethernet SwitchingEtherSwitch network modules support simultaneous, parallel connections between Layer 2 Ethernet segments. Switched connections between Ethernet segments last only for the duration of the packet. New connections can be made between different segments for the next packet.
The EtherSwitch network module solves congestion problems caused by high-bandwidth devices and a large number of users by assigning each device (for example, a server) to its own 10-, 100-, or 1000-Mbps segment. Because each Ethernet interface on the switch represents a separate Ethernet segment, servers in a properly configured switched environment achieve full access to the bandwidth.
Because collisions are a major bottleneck in Ethernet networks, an effective solution is full-duplex communication. Normally, Ethernet operates in half-duplex mode, which means that stations can either receive or transmit. In full-duplex mode, two stations can transmit and receive at the same time. When packets can flow in both directions simultaneously, effective Ethernet bandwidth doubles to 20 Mbps for 10-Mbps interfaces and to 200 Mbps for Fast Ethernet interfaces.
Switching Frames Between Segments
Each Ethernet interface on an EtherSwitch network module can connect to a single workstation or server, or to a hub through which workstations or servers connect to the network.
On a typical Ethernet hub, all ports connect to a common backplane within the hub, and the bandwidth of the network is shared by all devices attached to the hub. If two stations establish a session that uses a significant level of bandwidth, the network performance of all other stations attached to the hub is degraded.
To reduce degradation, the switch treats each interface as an individual segment. When stations on different interfaces need to communicate, the switch forwards frames from one interface to the other at wire speed to ensure that each session receives full bandwidth.
To switch frames between interfaces efficiently, the switch maintains an address table. When a frame enters the switch, it associates the MAC address of the sending station with the interface on which it was received.
Building the Address Table
The EtherSwitch network module builds the address table by using the source address of the frames received. When the switch receives a frame for a destination address not listed in its address table, it floods the frame to all interfaces of the same virtual local-area network (VLAN) except the interface that received the frame. When the destination station replies, the switch adds its relevant source address and interface ID to the address table. The switch then forwards subsequent frames to a single interface without flooding to all interfaces. The address table can store at least 8,191 address entries without flooding any entries. The switch uses an aging mechanism, defined by a configurable aging timer; so if an address remains inactive for a specified number of seconds, it is removed from the address table.
Note Default parameters on the aging timer are recommended.
VLAN Trunks
A trunk is a point-to-point link between one or more Ethernet switch interfaces and another networking device such as a router or a switch. Trunks carry the traffic of multiple VLANs over a single link and allow you to extend VLANs across an entire network and supports only one encapsulation on all Ethernet interfaces: 802.1Q-802.1Q is an industry-standard trunking encapsulation. You can configure a trunk on a single Ethernet interface or on an EtherChannel bundle.
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Layer 2 Interface Modes
Two Ethernet interface modes can be configured. Using the switchport command with the mode access keywords puts the interface into nontrunking mode. The interface will stay in access mode regardless of what the connected port mode is. Only access VLAN traffic will travel on the access port and untagged (802.3).
Using the switchport command with the mode trunk keywords puts the interface into permanent trunking mode.
Table 14 Default Layer 2 Ethernet Interface Configuration
When you connect a Cisco switch to a device other than a Cisco device through an 802.1Q trunk, the Cisco switch combines the spanning tree instance of the VLAN trunk with the spanning tree instance of the other 802.1Q switch. However, spanning tree information for each VLAN is maintained by Cisco switches separated by a cloud of 802.1Q switches that are not Cisco switches. The 802.1Q cloud separating the Cisco switches that is not Cisco devised, is treated as a single trunk link between the switches.
Make sure that the native VLAN for an 802.1Q trunk is the same on both ends of the trunk link. If the VLAN on one end of the trunk is different from the VLAN on the other end, spanning tree loops might result. Inconsistencies detected by a Cisco switch mark the line as broken and block traffic for the specific VLAN.
Disabling spanning tree on the VLAN of an 802.1Q trunk without disabling spanning tree on every VLAN in the network can potentially cause spanning tree loops. Cisco recommends that you leave spanning tree enabled on the VLAN of an 802.1Q trunk or that you disable spanning tree on every VLAN in the network. Make sure that your network is loop-free before disabling spanning tree.
Layer 2 Interface Configuration Guidelines and Restrictions
Follow these guidelines and restrictions when configuring Layer 2 interfaces:
In a network of Cisco switches connected through 802.1Q trunks, the switches maintain one instance of spanning tree for each VLAN allowed on the trunks. 802.1Q switches that are not Cisco switches, maintain only one instance of spanning tree for all VLANs allowed on the trunks.
Feature Default Value
Interface mode switchport mode access or trunk
Trunk encapsulation switchport trunk encapsulation dot1q
Allowed VLAN range VLANs 1-1005
Default VLAN (for access ports) VLAN 1
Native VLAN (for 802.1Q trunks) VLAN 1
Spanning Tree Protocol (STP) Enabled for all VLANs
STP port priority 128
STP port cost 100 for 10-Mbps Ethernet interfaces
19 for 10/100-Mbps Fast Ethernet interfaces
19 for Gigabit Ethernet interfaces operated in 100-Mb mode
4 for Gigabit Ethernet interfaces operated in 1000-Mb mode
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Cisco Discovery ProtocolCisco Discovery Protocol (CDP) is a protocol that runs over Layer 2 (the data link layer) on all Cisco routers, bridges, access servers, and switches. CDP allows network management applications to discover Cisco devices that are neighbors of already known devices, in particular, neighbors running lower-layer, transparent protocols. With CDP, network management applications can learn the device type and the SNMP agent address of neighboring devices. This feature enables applications to send SNMP queries to neighboring devices.
CDP runs on all LAN and WAN media that support Subnetwork Access Protocol (SNAP). Each CDP-configured device sends periodic messages to a multicast address. Each device advertises at least one address at which it can receive SNMP messages. The advertisements also contain the time-to-live, or hold-time information, which indicates the length of time a receiving device should hold CDP information before discarding it.
Port SecurityYou can use port security to block input to an Ethernet, Fast Ethernet, or Gigabit Ethernet port when the MAC address of the station attempting to access the port is different from any of the MAC addresses specified for that port. Alternatively, you can use port security to filter traffic destined to or received from a specific host based on the host MAC address.
802.1x AuthenticationThis section describes how to configure IEEE 802.1x port-based authentication to prevent unauthorized devices (clients) from gaining access to the network. As LANs extend to hotels, airports, and corporate lobbies, insecure environments could be created.
Understanding 802.1x Port-Based Authentication
The IEEE 802.1x standard defines a client/server-based access control and authentication protocol that restricts unauthorized devices from connecting to a LAN through publicly accessible ports. The authentication server authenticates each client connected to a switch port before making available any services offered by the switch or the LAN.
Until the client is authenticated, 802.1x access control allows only Extensible Authentication Protocol over LAN (EAPOL) traffic through the port to which the client is connected. After authentication is successful, normal traffic can pass through the port.
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Device Roles
With 802.1x port-based authentication, the devices in the network have specific roles as shown in Figure 29.
Figure 29 802.1x Device Roles
• Client—the device (workstation) that requests access to the LAN and switch services and responds to the requests from the switch. The workstation must be running 802.1x-compliant client software such as that offered in the Microsoft Windows XP operating system. (The client is the supplicant in the IEEE 802.1x specification.)
Note To resolve Windows XP network connectivity and 802.1x authentication issues, read the Microsoft Knowledge Base article at this URL:http://support.microsoft.com/support/kb/articles/Q303/5/97.ASP
• Authentication server—performs the actual authentication of the client. The authentication server validates the identity of the client and notifies the switch whether or not the client is authorized to access the LAN and switch services. Because the switch acts as the proxy, the authentication service is transparent to the client. In this release, the Remote Authentication Dial-In User Service (RADIUS) security system with Extensible Authentication Protocol (EAP) extensions is the only supported authentication server; it is available in Cisco Secure Access Control Server version 3.0. RADIUS operates in a client/server model in which secure authentication information is exchanged between the RADIUS server and one or more RADIUS clients.
• Switch (edge switch or wireless access point)—controls the physical access to the network based on the authentication status of the client. The switch acts as an intermediary (proxy) between the client and the authentication server, requesting identity information from the client, verifying that information with the authentication server, and relaying a response to the client. The switch includes the RADIUS client, which is responsible for encapsulating and decapsulating the Extensible Authentication Protocol (EAP) frames and interacting with the authentication server.
When the switch receives EAPOL frames and relays them to the authentication server, the Ethernet header is stripped and the remaining EAP frame is reencapsulated in the RADIUS format. The EAP frames are not modified or examined during encapsulation, and the authentication server must support EAP within the native frame format. When the switch receives frames from the authentication server, the server’s frame header is removed, leaving the EAP frame, which is then encapsulated for Ethernet and sent to the client.
The devices that can act as intermediaries include the Catalyst 3550 multilayer switch, Catalyst 2950 switch, or a wireless access point. These devices must be running software that supports the RADIUS client and 802.1x.
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Authentication Initiation and Message Exchange
The switch or the client can initiate authentication. If you enable authentication on a port by using the dot1x port-control auto interface configuration command, the switch must initiate authentication when it determines that the port link state changes from down to up. It then sends an EAP-request/identity frame to the client to request its identity (typically, the switch sends an initial identity/request frame followed by one or more requests for authentication information). Upon receipt of the frame, the client responds with an EAP-response/identity frame.
However, if during bootup, the client does not receive an EAP-request/identity frame from the switch, the client can initiate authentication by sending an EAPOL-start frame, which prompts the switch to request the client’s identity.
Note If 802.1x is not enabled or supported on the network access device, any EAPOL frames from the client are dropped. If the client does not receive an EAP-request/identity frame after three attempts to start authentication, the client transmits frames as if the port is in the authorized state. A port in the authorized state effectively means that the client has been successfully authenticated.
When the client supplies its identity, the switch begins its role as the intermediary, passing EAP frames between the client and the authentication server until authentication succeeds or fails. If the authentication succeeds, the switch port becomes authorized.
The specific exchange of EAP frames depends on the authentication method being used. Figure 30 shows a message exchange initiated by the client using the One-Time-Password (OTP) authentication method with a RADIUS server.
Figure 30 Message Exchange
Client
Port Authorized
Port Unauthorized
EAPOL-Start
EAP-Request/Identity
EAP-Response/Identity
EAP-Request/OTP
EAP-Response/OTP
EAP-Success
RADIUS Access-Request
RADIUS Access-Challenge
RADIUS Access-Request
RADIUS Access-Accept
EAPOL-Logoff
Authenticationserver
(RADIUS)15
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Ports in Authorized and Unauthorized States
The switch port state determines whether or not the client is granted access to the network. The port starts in the unauthorized state. While in this state, the port disallows all ingress and egress traffic except for 802.1x packets. When a client is successfully authenticated, the port changes to the authorized state, allowing all traffic for the client to flow normally.
If a client that does not support 802.1x is connected to an unauthorized 802.1x port, the switch requests the client’s identity. In this situation, the client does not respond to the request, the port remains in the unauthorized state, and the client is not granted access to the network.
In contrast, when an 802.1x-enabled client connects to a port that is not running 802.1x, the client initiates the authentication process by sending the EAPOL-start frame. When no response is received, the client sends the request for a fixed number of times. Because no response is received, the client begins sending frames as if the port is in the authorized state.
If the client is successfully authenticated (receives an Accept frame from the authentication server), the port state changes to authorized, and all frames from the authenticated client are allowed through the port. If the authentication fails, the port remains in the unauthorized state, but authentication can be retried. If the authentication server cannot be reached, the switch can retransmit the request. If no response is received from the server after the specified number of attempts, authentication fails, and network access is not granted.
When a client logs off, it sends an EAPOL-logoff message, causing the switch port to change to the unauthorized state.
If the link state of a port changes from up to down, or if an EAPOL-logoff frame is received, the port returns to the unauthorized state.
Supported Topologies
The 802.1x port-based authentication is supported in two topologies:
• Point-to-point
• Wireless LAN
In a point-to-point configuration (see Figure 29 on page 219), only one client can be connected to the 802.1x-enabled switch port. The switch detects the client when the port link state changes to the up state. If a client leaves or is replaced with another client, the switch changes the port link state to down, and the port returns to the unauthorized state.
Figure 31 shows 802.1x-port-based authentication in a wireless LAN. The 802.1x port is configured as a multiple-host port that becomes authorized as soon as one client is authenticated. When the port is authorized, all other hosts indirectly attached to the port are granted access to the network. If the port becomes unauthorized (reauthentication fails or an EAPOL-logoff message is received), the switch denies access to the network to all of the attached clients. In this topology, the wireless access point is responsible for authenticating the clients attached to it, and the wireless access point acts as a client to the switch.
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Figure 31 Wireless LAN Example
Storm ControlA traffic storm occurs when packets flood the LAN, creating excessive traffic and degrading network performance. Errors in the protocol-stack implementation or in the network configuration can cause a storm. Storm control can be implemented globally or on a per-port basis. Global storm control and per-port storm control cannot be enabled at the same time.
Global Storm Control
Global storm control prevents switchports on a LAN from being disrupted by a broadcast, multicast, or unicast storm on one of the interfaces. Global storm control monitors incoming traffic statistics over a time period and compares the measurement with a predefined suppression level threshold. The threshold represents the percentage of the total available bandwidth of the port. If the threshold of a traffic type is reached, further traffic of that type is suppressed until the incoming traffic falls below the threshold level. Global storm control is disabled by default.
The switch supports global storm control for broadcast, multicast, and unicast traffic. This example of broadcast suppression can also be applied to multicast and unicast traffic.
The graph in Figure 32 shows broadcast traffic patterns on an interface over a given period of time. In this example, the broadcast traffic exceeded the configured threshold between time intervals T1 and T2 and between T4 and T5. When the amount of specified traffic exceeds the threshold, all traffic of that kind is dropped. Therefore, broadcast traffic is blocked during those intervals. At the next time interval, if broadcast traffic does not exceed the threshold, it is again forwarded.
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Figure 32 Broadcast Suppression Example
When global storm control is enabled, the switch monitors packets passing from an interface to the switching bus and determines if the packet is unicast, multicast, or broadcast. The switch monitors the number of broadcast, multicast, or unicast packets received within the 1-second time interval, and when a threshold for one type of traffic is reached, that type of traffic is dropped. This threshold is specified as a percentage of total available bandwidth that can be used by broadcast (multicast or unicast) traffic.
The combination of broadcast suppression threshold numbers and the 1-second time interval control the way the suppression algorithm works. A higher threshold allows more packets to pass through. A threshold value of 100 percent means that no limit is placed on the traffic.
Note Because packets do not arrive at uniform intervals, the 1-second time interval during which traffic activity is measured can affect the behavior of global storm control.
The switch continues to monitor traffic on the port, and when the utilization level is below the threshold level, the type of traffic that was dropped is forwarded again.
Per-Port Storm Control
A packet storm occurs when a large number of broadcast, unicast, or multicast packets are received on a port. Forwarding these packets can cause the network to slow down or to time out. By default, per-port storm control is disabled.
Per-port storm control uses rising and falling thresholds to block and then restore the forwarding of broadcast, unicast, or multicast packets. You can also set the switch to shut down the port when the rising threshold is reached.
Per-port storm control uses a bandwidth-based method to measure traffic activity. The thresholds are expressed as a percentage of the total available bandwidth that can be used by the broadcast, multicast, or unicast traffic.
The rising threshold is the percentage of total available bandwidth associated with multicast, broadcast, or unicast traffic before forwarding is blocked. The falling threshold is the percentage of total available bandwidth below which the switch resumes normal forwarding. In general, the higher the level, the less effective the protection against broadcast storms.
Totalnumber of broadcastpackets or bytes
Forwarded traffic
0 T1
Threshold
T2 T4 T5 4665
1
T3 Time
Blocked traffic
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EtherChannelEtherChannel bundles up to eight individual Ethernet links into a single logical link that provides bandwidth of up to 1600 Mbps (Fast EtherChannel full duplex) between the network module and another switch or host.
An EtherSwitch network module system supports a maximum of six EtherChannels. All interfaces in each EtherChannel must have the same speed duplex and mode.
Load Balancing
EtherChannel balances traffic load across the links in a channel by reducing part of the binary pattern formed from the addresses in the frame to a numerical value that selects one of the links in the channel.
EtherChannel load balancing can use MAC addresses or IP addresses; either source or destination or both source and destination. The selected mode applies to all EtherChannels configured on the switch.
Use the option that provides the greatest variety in your configuration. For example, if the traffic on a channel is going only to a single MAC address, using the destination MAC address always chooses the same link in the channel; using source addresses or IP addresses may result in better load balancing.
EtherChannel Configuration Guidelines and Restrictions
If improperly configured, some EtherChannel interfaces are disabled automatically to avoid network loops and other problems. Follow these guidelines and restrictions to avoid configuration problems:
• All Ethernet interfaces on all modules support EtherChannel (maximum of eight interfaces) with no requirement that interfaces be physically contiguous or on the same module.
• Configure all interfaces in an EtherChannel to operate at the same speed and duplex mode.
• Enable all interfaces in an EtherChannel. If you shut down an interface in an EtherChannel, it is treated as a link failure and its traffic is transferred to one of the remaining interfaces in the EtherChannel.
• An EtherChannel will not form if one of the interfaces is a Switched Port Analyzer (SPAN) destination port.
For Layer 2 EtherChannels:
• Assign all interfaces in the EtherChannel to the same VLAN, or configure them as trunks.
An EtherChannel supports the same allowed range of VLANs on all interfaces in a trunking Layer 2 EtherChannel. If the allowed range of VLANs is not the same, the interfaces do not form an EtherChannel.
Interfaces with different Spanning Tree Protocol (STP) port path costs can form an EtherChannel as long they are otherwise compatibly configured. Setting different STP port path costs does not, by itself, make interfaces incompatible for the formation of an EtherChannel.
After you configure an EtherChannel, configuration that you apply to the port-channel interface affects the EtherChannel.
Flow Control on Gigabit Ethernet PortsFlow control is a feature that Gigabit Ethernet ports use to inhibit the transmission of incoming packets. If a buffer on a Gigabit Ethernet port runs out of space, the port transmits a special packet that requests remote ports to delay sending packets for a period of time. This special packet is called a pause frame. The send and receive keywords of the set port flowcontrol command are used to specify the behavior of the pause frames.
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Intrachassis StackingMultiple switch modules may be installed simultaneously by connecting the Gigabit Ethernet (GE) ports of the EtherSwitch network module. This connection sustains a line-rate traffic similar to the switch fabric found in Cisco Catalyst switches and forms a single VLAN consisting of all ports in multiple EtherSwitch network modules. The stacking port must be configured for multiple switch modules to operate correctly in the same chassis.
• MAC address entries learned via intrachassis stacking are not displayed.
• Link status of intrachassis stacked ports are filtered.
Switched Port Analyzer
Switched Port Analyzer Session
A Switched Port Analyzer (SPAN) session is an association of a destination interface with a set of source interfaces. You configure SPAN sessions using parameters that specify the type of network traffic to monitor. SPAN sessions allow you to monitor traffic on one or more interfaces and to send either ingress traffic, egress traffic, or both to one destination interface. You can configure one SPAN session with separate or overlapping sets of SPAN source interfaces or VLANs. Only switched interfaces can be configured as SPAN sources or destinations on the same network module.
SPAN sessions do not interfere with the normal operation of the switch. You can enable or disable SPAN sessions with command-line interface (CLI) or SNMP commands. When enabled, a SPAN session might become active or inactive based on various events or actions, and this would be indicated by a syslog message. The show monitor session command displays the operational status of a SPAN session.
A SPAN session remains inactive after system power-up until the destination interface is operational.
Destination Interface
A destination interface (also called a monitor interface) is a switched interface to which SPAN sends packets for analysis. You can have one SPAN destination interface. Once an interface becomes an active destination interface, incoming traffic is disabled. You cannot configure a SPAN destination interface to receive ingress traffic. The interface does not forward any traffic except that required for the SPAN session.
An interface configured as a destination interface cannot be configured as a source interface. EtherChannel interfaces cannot be SPAN destination interfaces.
Specifying a trunk interface as a SPAN destination interface stops trunking on the interface.
Source Interface
A source interface is an interface monitored for network traffic analysis. One or more source interfaces can be monitored in a single SPAN session with user-specified traffic types (ingress, egress, or both) applicable for all the source interfaces.
You can configure source interfaces in any VLAN. You can configure EtherChannel as source interfaces, which means that all interfaces in the specified VLANs are source interfaces for the SPAN session.
Trunk interfaces can be configured as source interfaces and mixed with nontrunk source interfaces; however, the destination interface never encapsulates.
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Traffic Types
Ingress SPAN (Rx) copies network traffic received by the source interfaces for analysis at the destination interface. Egress SPAN (Tx) copies network traffic transmitted from the source interfaces. Specifying the configuration option both copies network traffic received and transmitted by the source interfaces to the destination interface.
SPAN Traffic
Network traffic, including multicast, can be monitored using SPAN. Multicast packet monitoring is enabled by default. In some SPAN configurations, multiple copies of the same source packet are sent to the SPAN destination interface. For example, a bidirectional (both ingress and egress) SPAN session is configured for sources a1 and a2 to a destination interface d1. If a packet enters the switch through a1 and gets switched to a2, both incoming and outgoing packets are sent to destination interface d1; both packets would be the same (unless a Layer-3 rewrite had occurred, in which case the packets would be different).
Note Monitoring of VLANs is not supported.
SPAN Configuration Guidelines and Restrictions
Follow these guidelines and restrictions when configuring SPAN:
• Enter the no monitor session session number command with no other parameters to clear the SPAN session number.
• EtherChannel interfaces can be SPAN source interfaces; they cannot be SPAN destination interfaces.
• If you specify multiple SPAN source interfaces, the interfaces can belong to different VLANs.
• Monitoring of VLANs is not supported
• Only one SPAN session may be run at any given time.
• Outgoing CDP and BPDU packets will not be replicated.
• SPAN destinations never participate in any spanning tree instance. SPAN includes BPDUs in the monitored traffic, so any BPDUs seen on the SPAN destination are from the SPAN source.
• Use a network analyzer to monitor interfaces.
• You can have one SPAN destination interface.
• You can mix individual source interfaces within a single SPAN session.
• You cannot configure a SPAN destination interface to receive ingress traffic.
• When enabled, SPAN uses any previously entered configuration.
• When you specify source interfaces and do not specify a traffic type (Tx, Rx, or both), both is used by default.
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Switched Virtual InterfaceA switch virtual interface (SVI) represents a VLAN of switch ports as one interface to the routing or bridging function in the system. Only one SVI can be associated with a VLAN, but it is necessary to configure an SVI for a VLAN only when you wish to route between VLANs, fallback-bridge nonroutable protocols between VLANs, or to provide IP host connectivity to the switch. By default, an SVI is created for the default VLAN (VLAN 1) to permit remote switch administration. Additional SVIs must be explicitly configured. You can configure routing across SVIs.
SVIs are created the first time that you enter the vlan interface configuration command for a VLAN interface. The VLAN corresponds to the VLAN tag associated with data frames on an ISL or 802.1Q encapsulated trunk or the VLAN ID configured for an access port. Configure a VLAN interface for each VLAN for which you want to route traffic, and assign it an IP address.
SVIs support routing protocol and bridging configurations. For more information about configuring IP routing across SVIs, see the “Enabling and Verifying IP Multicast Layer 3 Switching” section on page 290.
Routed PortsA routed port is a physical port that acts like a port on a router; it does not have to be connected to a router. A routed port is not associated with a particular VLAN, as is an access port. A routed port behaves like a regular router interface, except that it does not support subinterfaces. Routed ports can be configured with a Layer 3 routing protocol.
Configure routed ports by putting the interface into Layer 3 mode with the no switchport interface configuration command. Then assign an IP address to the port, enable routing, and assign routing protocol characteristics by using the ip routing and router protocol global configuration commands.
Caution Entering a no switchport interface configuration command shuts the interface down and then reenables it, which might generate messages on the device to which the interface is connected. Furthermore, when you use this command to put the interface into Layer 3 mode, you are deleting any Layer 2 characteristics configured on the interface. (Also, when you return the interface to Layer 2 mode, you are deleting any Layer 3 characteristics configured on the interface.)
The number of routed ports and SVIs that you can configure is not limited by software; however, the interrelationship between this number and the number of other features being configured might have an impact on CPU utilization because of hardware limitations.
Routed ports support only Cisco Express Forwarding (CEF) switching (IP fast switching is not supported).
IP Multicast Layer 3 SwitchingThe maximum number of configured VLANs must be less than or equal to 242. The maximum number of multicast groups is related to the maximum number of VLANs. The number of VLANs is determined by multiplying the number of VLANs by the number of multicast groups. For example, the maximum number for 10 VLANs and 20 groups would be 200, under the 242 limit. This feature also provides support for Protocol Independent Multicast (PIM) sparse mode/dense mode/sparse-dense mode.
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IGMP SnoopingInternet Group Management Protocol (IGMP) snooping constrains the flooding of multicast traffic by dynamically configuring the interfaces so that multicast traffic is forwarded only to those interfaces associated with IP multicast devices. The LAN switch snoops on the IGMP traffic between the host and the router and keeps track of multicast groups and member ports. When the switch receives an IGMP join report from a host for a particular multicast group, the switch adds the host port number to the associated multicast forwarding table entry. When it receives an IGMP Leave Group message from a host, it removes the host port from the table entry. After it relays the IGMP queries from the multicast router, it deletes entries periodically if it does not receive any IGMP membership reports from the multicast clients.
When IGMP snooping is enabled, the multicast router sends out periodic IGMP general queries to all VLANs. The switch responds to the router queries with only one join request per MAC multicast group, and the switch creates one entry per VLAN in the Layer 2 forwarding table for each MAC group from which it receives an IGMP join request. All hosts interested in this multicast traffic send join requests and are added to the forwarding table entry.
Layer 2 multicast groups learned through IGMP snooping are dynamic. However, you can statically configure MAC multicast groups by using the ip igmp snooping vlan static command. If you specify group membership for a multicast group address statically, your setting supersedes any automatic manipulation by IGMP snooping. Multicast group membership lists can consist of both user-defined and IGMP snooping-learned settings.
EtherSwitch network modules support a maximum of 255 IP multicast groups and support both IGMP version 1 and IGMP version 2.
If a port spanning-tree, a port group, or a VLAN ID change occurs, the IGMP snooping-learned multicast groups from this port on the VLAN are deleted.
In the IP multicast-source-only environment, the switch learns the IP multicast group from the IP multicast data stream and only forwards traffic to the multicast router ports.
Immediate-Leave Processing
IGMP snooping Immediate-Leave processing allows the switch to remove an interface that sends a leave message from the forwarding table without first sending out MAC-based general queries to the interface. The VLAN interface is pruned from the multicast tree for the multicast group specified in the original leave message. Immediate-Leave processing ensures optimal bandwidth management for all hosts on a switched network, even when multiple multicast groups are in use simultaneously.
Note You should use the Immediate-Leave processing feature only on VLANs where only one host is connected to each port. If Immediate-Leave processing is enabled on VLANs where more than one host is connected to a port, some hosts might be inadvertently dropped. Immediate-Leave processing is supported only with IGMP version 2 hosts.
Setting the Snooping Method
Multicast-capable router ports are added to the forwarding table for every IP multicast entry. The switch learns of such ports through one of these methods:
• Snooping on PIM and DVMRP packets
• Statically connecting to a multicast router port with the ip igmp snooping mrouter global configuration command
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You can configure the switch to snoop on PIM/Distance Vector Multicast Routing Protocol (PIM/DVMRP) packets. By default, the switch snoops on PIM/DVMRP packets on all VLANs. To learn of multicast router ports through PIM-DVMRP packets, use the ip igmp snooping vlan vlan-id mrouter learn pim-dvmrp interface configuration command.
Joining a Multicast Group
When a host connected to the switch wants to join an IP multicast group, it sends an IGMP join message, specifying the IP multicast group it wants to join. When the switch receives this message, it adds the port to the IP multicast group port address entry in the forwarding table.
Refer to Figure 33. Host 1 wants to join multicast group 224.1.2.3 and send a multicast message of an unsolicited IGMP membership report (IGMP join message) to the group with the equivalent MAC destination address of 0100.5E01.0203. The switch recognizes IGMP packets and forwards them to the CPU. When the CPU receives the IGMP multicast report by Host 1, the CPU uses the information to set up a multicast forwarding table entry as shown in Table 15 that includes the port numbers of Host 1 and the router.
Figure 33 Initial IGMP Join Message
Note that the switch architecture allows the CPU to distinguish IGMP information packets from other packets for the multicast group. The switch recognizes the IGMP packets through its filter engine. This prevents the CPU from becoming overloaded with multicast frames.
The entry in the multicast forwarding table tells the switching engine to send frames addressed to the 0100.5E01.0203 multicast MAC address that are not IGMP packets (!IGMP) to the router and to the host that has joined the group.
Table 15 IP Multicast Forwarding Table
Destination Address Type of Packet Ports
0100.5e01.0203 !IGMP 1, 2
MulticastForwarding
Table
Host 1 Host 2 Host 3 Host 4
IGMP Report 224.1.2.31
CPU port
2 3 4 5
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If another host (for example, Host 4) sends an IGMP join message for the same group (Figure 34), the CPU receives that message and adds the port number of Host 4 to the multicast forwarding table as shown in Table 16.
Figure 34 Second Host Joining a Multicast Group
Leaving a Multicast Group
The router sends periodic IP multicast general queries, and the switch responds to these queries with one join response per MAC multicast group. As long as at least one host in the VLAN needs multicast traffic, the switch responds to the router queries, and the router continues forwarding the multicast traffic to the VLAN. The switch only forwards IP multicast group traffic to those hosts listed in the forwarding table for that IP multicast group.
When hosts need to leave a multicast group, they can either ignore the periodic general-query requests sent by the router, or they can send a leave message. When the switch receives a leave message from a host, it sends out a group-specific query to determine if any devices behind that interface are interested in traffic for the specific multicast group. If, after a number of queries, the router processor receives no reports from a VLAN, it removes the group for the VLAN from its multicast forwarding table.
Fallback BridgingWith fallback bridging, the switch bridges together two or more VLANs or routed ports, essentially connecting multiple VLANs within one bridge domain. Fallback bridging forwards traffic that the multilayer switch does not route and forwards traffic belonging to a nonroutable protocol such as DECnet.
Table 16 Updated Multicast Forwarding Table
Destination Address Type of Packet Ports
0100.5e01.0203 !IGMP 1, 2, 5
Host 1 Host 2 Host 3 Host 4
1
2 3 4 5
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MulticastForwarding
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Fallback bridging does not allow the spanning trees from the VLANs being bridged to collapse; each VLAN has its own Spanning Tree Protocol (STP) instance and a separate spanning tree, called the VLAN-bridge spanning tree, which runs on top of the bridge group to prevent loops.
A VLAN bridge domain is represented using the switch virtual interface (SVI). A set of SVIs and routed ports (which do not have any VLANs associated with them) can be configured to form a bridge group.
Recall that an SVI represents a VLAN of switch ports as one interface to the routing or bridging function in the system. Only one SVI can be associated with a VLAN, and it is only necessary to configure an SVI for a VLAN when you want to route between VLANs, to fallback-bridge nonroutable protocols between VLANs, or to provide IP host connectivity to the switch. A routed port is a physical port that acts like a port on a router, but it is not connected to a router. A routed port is not associated with a particular VLAN, does not support subinterfaces, but behaves like a normal routed interface.
A bridge group is an internal organization of network interfaces on a switch. Bridge groups cannot be used to identify traffic switched within the bridge group outside the switch on which they are defined. Bridge groups on the same switch function as distinct bridges; that is, bridged traffic and bridge protocol data units (BPDUs) cannot be exchanged between different bridge groups on a switch. An interface can be a member of only one bridge group. Use a bridge group for each separately bridged (topologically distinct) network connected to the switch.
The purpose of placing network interfaces into a bridge group is twofold:
• To bridge all nonrouted traffic among the network interfaces making up the bridge group. If the packet destination address is in the bridge table, it is forwarded on a single interface in the bridge group. If the packet destination address is not in the bridge table, it is flooded on all forwarding interfaces in the bridge group. The bridge places source addresses in the bridge table as it learns them during the bridging process.
• To participate in the spanning-tree algorithm by receiving, and in some cases sending, BPDUs on the LANs to which they are attached. A separate spanning process runs for each configured bridge group. Each bridge group participates in a separate spanning-tree instance. A bridge group establishes a spanning-tree instance based on the BPDUs it receives on only its member interfaces.
Figure 35 shows a fallback bridging network example. The multilayer switch has two interfaces configured as SVIs with different assigned IP addresses and attached to two different VLANs. Another interface is configured as a routed port with its own IP address. If all three of these ports are assigned to the same bridge group, non-IP protocol frames can be forwarded among the end stations connected to the switch.
Figure 35 Fallback Bridging Network Example
Host A
Host C
SVI 1172.20.128.1 172.20.129.1
Routed port172.20.130.1
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VLAN 30
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Network Security with ACLs at Layer 2Network security on your EtherSwitch network module can be implemented using access control lists (ACLs), which are also referred to in commands and tables as access lists.
Understanding ACLs
Packet filtering can limit network traffic and restrict network use by certain users or devices. ACLs can filter traffic as it passes through a switch and permit or deny packets from crossing specified interfaces. An ACL is a sequential collection of permit and deny conditions that apply to packets. When a packet is received on an interface, the switch compares the fields in the packet against any applied ACLs to verify that the packet has the required permissions to be forwarded, based on the criteria specified in the access lists. The switch tests the packet against the conditions in an access list one by one. The first match determines whether the switch accepts or rejects the packet. Because the switch stops testing conditions after the first match, the order of conditions in the list is critical. If no conditions match, the switch rejects the packet. If there are no restrictions, the switch forwards the packet; otherwise, the switch drops the packet.
You configure access lists on a Layer 2 switch to provide basic security for your network. If you do not configure ACLs, all packets passing through the switch could be allowed onto all parts of the network. You can use ACLs to control which hosts can access different parts of a network or to decide which types of traffic are forwarded or blocked at switch interfaces. For example, you can allow e-mail traffic to be forwarded but not Telnet traffic. ACLs can be configured to block inbound traffic.
An ACL contains an ordered list of access control entries (ACEs). Each ACE specifies permit or deny and a set of conditions the packet must satisfy in order to match the ACE. The meaning of permit or deny depends on the context in which the ACL is used.
The EtherSwitch network module supports IP ACLs to filter IP traffic, including TCP or User Datagram Protocol (UDP) traffic (but not both traffic types in the same ACL).
ACLs
You can apply ACLs on physical Layer 2 interfaces. ACLs are applied on interfaces only on the inbound direction.
• Standard IP access lists use source addresses for matching operations.
• Extended IP access lists use source and destination addresses and optional protocol type information for matching operations.
The switch examines access lists associated with features configured on a given interface and a direction. As packets enter the switch on an interface, ACLs associated with all inbound features configured on that interface are examined.
ACLs permit or deny packet forwarding based on how the packet matches the entries in the ACL. For example, you can use ACLs to allow one host to access a part of a network, but to prevent another host from accessing the same part. In Figure 36, ACLs applied at the switch input allow Host A to access the Human Resources network, but prevent Host B from accessing the same network.
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Figure 36 Using ACLs to Control Traffic to a Network
Handling Fragmented and Unfragmented Traffic
IP packets can be fragmented as they cross the network. When this happens, only the fragment containing the beginning of the packet contains the Layer 4 information, such as TCP or UDP port numbers, ICMP type and code, and so on. All other fragments are missing this information.
Some ACEs do not check Layer 4 information and therefore can be applied to all packet fragments. ACEs that do test Layer 4 information cannot be applied in the standard manner to most of the fragments in a fragmented IP packet. When the fragment contains no Layer 4 information and the ACE tests some Layer 4 information, the matching rules are modified:
• Permit ACEs that check the Layer 3 information in the fragment (including protocol type, such as TCP, UDP, and so on) are considered to match the fragment regardless of what the missing Layer 4 information might have been.
• Deny ACEs that check Layer 4 information never match a fragment unless the fragment contains Layer 4 information.
Consider access list 102, configured with these commands, applied to three fragmented packets:
Router(config)# access-list 102 permit tcp any host 10.1.1.1 eq smtpRouter(config)# access-list 102 deny tcp any host 10.1.1.2 eq telnetRouter(config)# access-list 102 deny tcp any any
Note In the first and second ACEs in the examples, the eq keyword after the destination address means to test for the TCP-destination-port well-known numbers equaling Simple Mail Transfer Protocol (SMTP) and Telnet, respectively.
• Packet A is a TCP packet from host 10.2.2.2, port 65000, going to host 10.1.1.1 on the SMTP port. If this packet is fragmented, the first fragment matches the first ACE (a permit), as if it were a complete packet because all Layer 4 information is present. The remaining fragments also match the
Host A
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first ACE, even though they do not contain the SMTP port information because the first ACE only checks Layer 3 information when applied to fragments. (The information in this example is that the packet is TCP and that the destination is 10.1.1.1.)
• Packet B is from host 10.2.2.2, port 65001, going to host 10.1.1.2 on the Telnet port. If this packet is fragmented, the first fragment matches the second ACE (a deny) because all Layer 3 and Layer 4 information is present. The remaining fragments in the packet do not match the second ACE because they are missing Layer 4 information.
• Because the first fragment was denied, host 10.1.1.2 cannot reassemble a complete packet, so packet B is effectively denied. However, the later fragments that are permitted will consume bandwidth on the network and resources of host 10.1.1.2 as it tries to reassemble the packet.
• Fragmented packet C is from host 10.2.2.2, port 65001, going to host 10.1.1.3, port FTP. If this packet is fragmented, the first fragment matches the third ACE (a deny). All other fragments also match the third ACE because that ACE does not check any Layer 4 information and because Layer 3 information in all fragments shows that they are being sent to host 10.1.1.3, and the earlier permit ACEs were checking different hosts.
Understanding Access Control Parameters
Before configuring ACLs on the EtherSwitch network module, you must have a thorough understanding of the Access Control Parameters (ACPs). ACPs are referred to as masks in the switch CLI commands, and output.
Each ACE has a mask and a rule. The Classification Field or mask is the field of interest on which you want to perform an action. The specific values associated with a given mask are called rules.
Packets can be classified on these Layer 3 and Layer 4 fields.
• Layer 3 fields:
– IP source address (Specify all 32 IP source address bits to define the flow, or specify a user-defined subnet. There are no restrictions on the IP subnet to be specified.)
– IP destination address (Specify all 32 IP destination address bits to define the flow, or specify a user-defined subnet. There are no restrictions on the IP subnet to be specified.)
You can use any combination or all of these fields simultaneously to define a flow.
• Layer 4 fields:
– TCP (You can specify a TCP source, destination port number, or both at the same time.)
– UDP (You can specify a UDP source, destination port number, or both at the same time.)
Note A mask can be a combination of multiple Layer 3 and Layer 4 fields.
There are two types of masks:
• User-defined mask—masks that are defined by the user.
• System-defined mask—these masks can be configured on any interface:
Router(config-ext-nacl)# permit tcp any any Router(config-ext-nacl)# deny tcp any any Router(config-ext-nacl)# permit udp any any Router(config-ext-nacl)# deny udp any any Router(config-ext-nacl)# permit ip any any Router(config-ext-nacl)# deny ip any any Router(config-ext-nacl)# deny any any Router(config-ext-nacl)# permit any any
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Note In an IP extended ACL (both named and numbered), a Layer 4 system-defined mask cannot precede a Layer 3 user-defined mask. For example, a Layer 4 system-defined mask such as permit tcp any any or deny udp any any cannot precede a Layer 3 user-defined mask such as permit ip 10.1.1.1 any. If you configure this combination, the ACL is not configured. All other combinations of system-defined and user-defined masks are allowed in security ACLs.
The EtherSwitch network module ACL configuration is consistent with Cisco Catalyst switches. However, there are significant restrictions as well as differences for ACL configurations on the EtherSwitch network module.
Guidelines for Configuring ACLs on the EtherSwitch network module
These configuration guidelines apply to ACL filters:
• Only one ACL can be attached to an interface.
• All ACEs in an ACL must have the same user-defined mask. However, ACEs can have different rules that use the same mask. On a given interface, only one type of user-defined mask is allowed, but you can apply any number of system-defined masks.
The following example shows the same mask in an ACL:
Router(config)# ip access-list extended acl2Router(config-ext-nacl)# permit tcp 10.1.1.1 0.0.0.0 any eq 80 Router(config-ext-nacl)# permit tcp 10.2.1.1 0.0.0.0 any eq 23
In this example, the first ACE permits all the TCP packets coming from the host 10.1.1.1 with a destination TCP port number of 80. The second ACE permits all TCP packets coming from the host 10.2.1.1 with a destination TCP port number of 23. Both the ACEs use the same mask; therefore, a EtherSwitch network module supports this ACL.
• Only four user-defined masks can be defined for the entire system. These can be used for either security or quality of service (QoS) but cannot be shared by QoS and security. You can configure as many ACLs as you require. However, a system error message appears if ACLs with more than four different masks are applied to interfaces.
Table 17 lists a summary of the ACL restrictions on EtherSwitch network modules.
Quality of Service for the EtherSwitch Network ModuleQuality of service (QoS) can be implemented on your EtherSwitch network module. With this feature, you can provide preferential treatment to certain types of traffic. Without QoS, the switch offers best-effort service to each packet, regardless of the packet contents or size. It transmits the packets without any assurance of reliability, delay bounds, or throughput.
Table 17 Summary of ACL Restrictions
Restriction Number Permitted
Number of user-defined masks allowed in an ACL 1
Number of ACLs allowed on an interface 1
Total number of user-defined masks for security and QoS allowed on a switch
4
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Understanding Quality of Service)
Typically, networks operate on a best-effort delivery basis, which means that all traffic has equal priority and an equal chance of being delivered in a timely manner. When congestion occurs, all traffic has an equal chance of being dropped.
With the QoS feature configured on your EtherSwitch network module, you can select specific network traffic, prioritize it according to its relative importance, and use congestion-management and congestion-avoidance techniques to provide preferential treatment. Implementing QoS in your network makes network performance more predictable and bandwidth utilization more effective.
The QoS implementation for this release is based on the DiffServ architecture, an emerging standard from the Internet Engineering Task Force (IETF). This architecture specifies that each packet is classified upon entry into the network. The classification is carried in the IP packet header, using six bits from the deprecated IP type of service (ToS) field to carry the classification (class) information. Classification can also be carried in the Layer 2 frame. These special bits in the Layer 2 frame or a Layer 3 packet are described here and shown in Figure 37:
• Prioritization values in Layer 2 frames:
Layer 2 802.1Q frame headers have a 2-byte Tag Control Information field that carries the CoS value in the three most-significant bits, which are called the User Priority bits. On interfaces configured as Layer 2 802.1Q trunks, all traffic is in 802.1Q frames except for traffic in the native VLAN.
Other frame types cannot carry Layer 2 CoS values.
Layer 2 CoS values range from 0 for low priority to 7 for high priority.
• Prioritization bits in Layer 3 packets:
Layer 3 IP packets can carry a Differentiated Services Code Point (DSCP) value. The supported DSCP values are 0, 8, 10, 16, 18, 24, 26, 32, 34, 40, 46, 48, and 56.
Figure 37 QoS Classification Layers in Frames and Packets
Note Layer 2 ISL Frame is not supported in this release.
6098
0
Encapsulated Packet
Layer 2header
IP header Data
Layer 2 802.1Q/P Frame
Preamble Start framedelimiter
DA
Len
SA Tag PT Data FCS
Layer 3 IPv4 Packet
Versionlength
ToS(1 byte)
ID Offset TTL Proto FCS IP-SA IP-DA Data
3 bits used for CoS (user priority)
DSCP
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Note Layer 3 IPv6 packets are dropped when received by the switch.
All switches and routers across the Internet rely on the class information to provide the same forwarding treatment to packets with the same class information and different treatment to packets with different class information. The class information in the packet can be assigned by end hosts or by switches or routers along the way, based on a configured policy, detailed examination of the packet, or both. Detailed examination of the packet is expected to happen closer to the edge of the network so that the core switches and routers are not overloaded.
Switches and routers along the path can use the class information to limit the amount of resources allocated per traffic class. The behavior of an individual device when handling traffic in the DiffServ architecture is called per-hop behavior. If all devices along a path provide a consistent per-hop behavior, you can construct an end-to-end QoS solution.
Implementing QoS in your network can be a simple or complex task and depends on the QoS features offered by your internetworking devices, the traffic types and patterns in your network, and the granularity of control you need over incoming and outgoing traffic.
The EtherSwitch network module can function as a Layer 2 switch connected to a Layer 3 router. When a packet enters the Layer 2 engine directly from a switch port, it is placed into one of four queues in the dynamic, 32-MB shared memory buffer. The queue assignment is based on the dot1p value in the packet. Any voice bearer packets that come in from the Cisco IP phones on the voice VLAN are automatically placed in the highest priority (Queue 3) based on the 802.1p value generated by the IP phone. The queues are then serviced on a weighted round robin (WRR) basis. The control traffic, which uses a CoS or ToS of 3, is placed in Queue 2.
Table 18 summarizes the queues, CoS values, and weights for Layer 2 QoS on the EtherSwitch network module.
Table 18 Queues, CoS values, and Weights for Layer 2 QoS
The weights specify the number of packets that are serviced in the queue before moving on to the next queue. Voice Realtime Transport Protocol (RTP) bearer traffic marked with a CoS or ToS of 5 and Voice Control plane traffic marked with a CoS/ToS of 3 are placed into the highest priority queues. If the queue has no packets to be serviced, it is skipped. Weighted Random Early Detection (WRED) is not supported on the Fast Ethernet ports.
You cannot configure port-based QoS on the Layer 2 switch ports.
Basic QoS Model
Figure 38 shows the basic QoS model. Actions at the ingress interface include classifying traffic, policing, and marking:
• Classifying distinguishes one kind of traffic from another. For more information, see the “Classification” section on page 238.
Queue Number CoS Value Weight
3 5,6,7 255
2 3,4 64
1 2 16
0 0,1 1
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• Policing determines whether a packet is in or out of profile according to the configured policer, and the policer limits the bandwidth consumed by a flow of traffic. The result of this determination is passed to the marker. For more information, see the “Policing and Marking” section on page 239.
• Marking evaluates the policer and configuration information for the action to be taken when a packet is out of profile and decides what to do with the packet (pass through a packet without modification, mark down the DSCP value in the packet, or drop the packet). For more information, see the “Policing and Marking” section on page 239.
Actions at the egress interface include queueing and scheduling:
• Queuing evaluates the CoS value and determines which of the four egress queues in which to place the packet.
• Scheduling services the four egress queues based on their configured WRR weights.
Figure 38 Basic QoS Model
Classification
Classification is the process of distinguishing one kind of traffic from another by examining the fields in the packet.
Classification occurs only on a physical interface basis. No support exists for classifying packets at the VLAN or the switched virtual interface level.
You specify which fields in the frame or packet that you want to use to classify incoming traffic.
Classification Based on QoS ACLs
You can use IP standard or IP extended ACLs to define a group of packets with the same characteristics (class). In the QoS context, the permit and deny actions in the access control entries (ACEs) have different meanings than with security ACLs:
• If a match with a permit action is encountered (first-match principle), the specified QoS-related action is taken.
• If no match with a permit action is encountered and all the ACEs have been examined, no QoS processing occurs on the packet.
• If multiple ACLs are configured on an interface, the packet matches the first ACL with a permit action, and QoS processing begins.
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Classification Policing
Actions at ingress Actions at egress
Mark
In profile orout of profile
Classifies the packet based on the ACL.
Determines if the packet is in profile or out of profile based on the policer associated with the filter.
Based on whether the packet is in or out of profile and the configured parameters, determines whether to pass through, mark down, or drop the packet. The DSCP and CoS are marked or changed accordingly.
Queuing andscheduling
Based on the CoS, determines into which of the egress queues to place the packet, then services the queues according to the configured weights.
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• Configuration of a deny action is not supported in QoS ACLs on the 16- and 36-port EtherSwitch network modules.
• System-defined masks are allowed in class maps with these restrictions:
– A combination of system-defined and user-defined masks cannot be used in the multiple class maps that are a part of a policy map.
– System-defined masks that are a part of a policy map must all use the same type of system mask. For example, a policy map cannot have a class map that uses the permit tcp any any ACE and another that uses the permit ip any any ACE.
– A policy map can contain multiple class maps that all use the same user-defined mask or the same system-defined mask.
Note For more information on the system-defined mask, see the “Understanding Access Control Parameters” section on page 234.
• For more information on ACL restrictions, see the “Guidelines for Configuring ACLs on the EtherSwitch network module” section on page 235.
After a traffic class has been defined with the ACL, you can attach a policy to it. A policy might contain multiple classes with actions specified for each one of them. A policy might include commands to rate-limit the class. This policy is then attached to a particular port on which it becomes effective.
You implement IP ACLs to classify IP traffic by using the access-list global configuration command.
Classification Based on Class Maps and Policy Maps
A class map is a mechanism that you use to isolate and name a specific traffic flow (or class) from all other traffic. The class map defines the criteria used to match against a specific traffic flow to further classify it; the criteria can include matching the access group defined by the ACL. If you have more than one type of traffic that you want to classify, you can create another class map and use a different name. After a packet is matched against the class-map criteria, you further classify it through the use of a policy map.
A policy map specifies which traffic class to act on. Actions can include setting a specific DSCP value in the traffic class or specifying the traffic bandwidth limitations and the action to take when the traffic is out of profile. Before a policy map can be effective, you must attach it to an interface.
The policy map can also contain commands that define the policer, the bandwidth limitations of the traffic, and the action to take if the limits are exceeded. For more information, see the “Policing and Marking” section on page 239.
A policy map also has these characteristics:
• A policy map can contain multiple class statements.
• A separate policy-map class can exist for each type of traffic received through an interface.
• A policy-map configuration state supersedes any actions due to an interface trust state.
For configuration information, see the “Configuring a QoS Policy” section on page 317.
Policing and Marking
Policing involves creating a policer that specifies the bandwidth limits for the traffic. Packets that exceed the limits are out of profile or nonconforming. Each policer specifies the action to take for packets that are in or out of profile. These actions, carried out by the marker, include dropping the packet, or marking down the packet with a new value that is user-defined.
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You can create this type of policer:
Individual—QoS applies the bandwidth limits specified in the policer separately to each matched traffic class. You configure this type of policer within a policy map by using the policy-map configuration command.
For non-IP traffic, you have these marking options:
• Use the port default. If the frame does not contain a CoS value, assign the default port CoS value to the incoming frame.
• Trust the CoS value in the incoming frame (configure the port to trust CoS). Layer 2 802.1Q frame headers carry the CoS value in the three most-significant bits of the Tag Control Information field. CoS values range from 0 for low priority to 7 for high priority.
The trust DSCP configuration is meaningless for non-IP traffic. If you configure a port with this option and non-IP traffic is received, the switch assigns the default port CoS value and classifies traffic based on the CoS value.
For IP traffic, you have these classification options:
• Trust the IP DSCP in the incoming packet (configure the port to trust DSCP), and assign the same DSCP to the packet for internal use. The IETF defines the six most-significant bits of the 1-byte type of service (ToS) field as the DSCP. The priority represented by a particular DSCP value is configurable. The supported DSCP values are 0, 8, 10, 16, 18, 24, 26, 32, 34, 40, 46, 48, and 56.
• Trust the CoS value (if present) in the incoming packet, and generate the DSCP by using the CoS-to-DSCP map.
When configuring policing and policers, keep these items in mind:
• By default, no policers are configured.
• Policers can only be configured on a physical port. There is no support for policing at a VLAN or switched virtual interface (SVI) level.
• Only one policer can be applied to a packet in the input direction.
• Only the average rate and committed burst parameters are configurable.
• Policing occurs on the ingress interfaces:
– 60 policers are supported on ingress Gigabit-capable Ethernet ports.
– 6 policers are supported on ingress 10/100 Ethernet ports.
– Granularity for the average burst rate is 1 Mbps for 10/100 ports and 8 Mbps for Gigabit Ethernet ports.
• On an interface configured for QoS, all traffic received through the interface is classified, policed, and marked according to the policy map attached to the interface. On a trunk interface configured for QoS, traffic in all VLANs received through the interface is classified, policed, and marked according to the policy map attached to the interface.
• VLAN-based egress DSCP-to-COS mapping is supported. DSCP-to-COS mapping occurs for all packets with a specific VLAN ID egressing from the CPU to the physical port. The packets can be placed in the physical port egress queue depending on the COS value. Packets are handled according to type of service.
Note No policers can be configured on the egress interface on EtherSwitch network modules.
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Mapping Tables
The EtherSwitch network modules support these types of marking to apply to the switch:
• CoS value to the DSCP value
• DSCP value to CoS value
Note An interface can be configured to trust either CoS or DSCP, but not both at the same time.
Before the traffic reaches the scheduling stage, QoS uses the configurable DSCP-to-CoS map to derive a CoS value from the internal DSCP value.
The CoS-to-DSCP and DSCP-to-CoS map have default values that might or might not be appropriate for your network.
How to Configure the EtherSwitch Network ModuleThis section contains the following tasks:
• Configuring VLANs, page 242 (required)
• Configuring VLAN Trunking Protocol, page 244 (optional)
• Configuring Spanning Tree on a VLAN, page 246 (required)
• Verifying Spanning Tree on a VLAN, page 249 (optional)
• Configuring Layer 2 Interfaces, page 251 (required)
• Configuring an Ethernet Interface as a Layer 2 Trunk, page 254 (optional)
• Configuring an Ethernet Interface as a Layer 2 Access, page 256 (optional)
• Configuring Separate Voice and Data VLANs, page 257 (optional)
• Configuring a Single Voice and Data VLAN, page 259 (optional)
• Managing the EtherSwitch network module, page 260 (required)
• Configuring Voice Ports, page 263 (required)
• Verifying Cisco Discovery Protocol, page 265 (optional)
• Configuring the MAC Table to Provide Port Security, page 266 (required)
• Configuring 802.1x Authentication, page 269 (optional)
• Configuring Power Management on the Interfaces, page 278 (optional)
• Configuring Storm Control, page 279 (optional)
• Configuring Layer 2 EtherChannels (Port-Channel Logical Interfaces), page 282 (required)
• Configuring Flow Control on Gigabit Ethernet Ports, page 285 (required)
• Configuring Intrachassis Stacking, page 286 (required)
• Configuring Switched Port Analyzer (SPAN), page 287 (required)
• Configuring Layer 3 Interfaces, page 288 (required)
• Enabling and Verifying IP Multicast Layer 3 Switching, page 290 (required)
• Configuring IGMP Snooping, page 292 (optional)
• Configuring Fallback Bridging, page 294 (optional)
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• Configuring Network Security with ACLs at Layer 2, page 301 (optional)
• Configuring Quality of Service (QoS) on the EtherSwitch network module, page 313 (optional)
• Configuring a QoS Policy, page 317 (optional)
Configuring VLANsPerform this task to configure the VLANs on an EtherSwitch network module.
VLAN Removal from the Database
When you delete a VLAN from a router with an EtherSwitch network module installed that is in VTP server mode, the VLAN is removed from all EtherSwitch routers and switches in the VTP domain. When you delete a VLAN from an EtherSwitch router or switch that is in VTP transparent mode, the VLAN is deleted only on that specific device.
You cannot delete the default VLANs for the different media types: Ethernet VLAN 1 and FDDI or Token Ring VLANs 1002 to 1005.
SUMMARY STEPS
1. enable
2. vlan database
3. vlan vlan-id [are hops] [backupcrf mode] [bridge type | number] [media type] [mtu mtu-size] [name vlan-name] [parent parent-vlan-id] [ring ring-number] [said sa-id-value] [state {suspend | active}] [stp type type] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]
4. no vlan vlan-id
5. exit
6. show vlan-switch [brief | id vlan | name name]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 vlan database
Example:Router# configure terminal
Enters VLAN configuration mode.
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Examples
Sample Output for the show vlan-switch Command
In the following example, output information is displayed to verify the VLAN configuration:
Router# show vlan-switch name vlan0003
VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa1/0, Fa1/1, Fa1/2, Fa1/3 Fa1/4, Fa1/5, Fa1/6, Fa1/7 Fa1/8, Fa1/9, Fa1/10, Fa1/11 Fa1/12, Fa1/13, Fa1/14, Fa1/151002 fddi-default active 1003 token-ring-default active 1004 fddinet-default active 1005 trnet-default active
VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------1 enet 100001 1500 - - - - - 1002 10031002 fddi 101002 1500 - - - - - 1 10031003 tr 101003 1500 1005 0 - - srb 1 1002
Step 3 vlan vlan-id [are hops] [backupcrf mode] [bridge type | number] [media type] [mtu mtu-size] [name vlan-name] [parent parent-vlan-id] [ring ring-number] [said sa-id-value] [state {suspend | active}] [stp type type] [tb-vlan1 tb-vlan1-id] [tb-vlan2 tb-vlan2-id]
Example:Router(vlan)# vlan 2 media ethernet name vlan1502
Configures a specific VLAN.
• In this example, Ethernet VLAN 2 is added with the name of vlan1502.
• The VLAN database is updated when you leave VLAN configuration mode.
Step 4 no vlan vlan-id
Example:Router(vlan)# no vlan 2
(Optional) Deletes a specific VLAN.
• In this example, VLAN 2 is deleted.
Step 5 exit
Example:Router(vlan)# exit
Exits VLAN configuration mode and returns the router to privileged EXEC mode.
Step 6 show vlan-switch [brief | id vlan | name name]
Example:Router# show vlan-switch name vlan0003
(Optional) Displays VLAN information.
• The optional brief keyword displays only a single line for each VLAN, naming the VLAN, status, and ports.
• The optional id keyword displays information about a single VLAN identified by VLAN ID number; valid values are from 1 to 1005.
• The optional name keyword displays information about a single VLAN identified by VLAN name; valid values are an ASCII string from 1 to 32 characters.
Command or Action Purpose
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1004 fdnet 101004 1500 - - 1 ibm - 0 0 1005 trnet 101005 1500 - - 1 ibm - 0 0
In the following example, the brief keyword is used to verify that VLAN 2 has been deleted:
Router# show vlan-switch brief
VLAN Name Status Ports---- -------------------------------- --------- -------------------------------1 default active Fa0/2, Fa0/9, Fa0/14, Gi0/03 VLAN0003 active Fa0/4, Fa0/5, Fa0/10, Fa0/114 VLAN0004 active Fa0/6, Fa0/7, Fa0/12, Fa0/135 VLAN0005 active40 VLAN0040 active Fa0/1550 VLAN0050 active1000 VLAN1000 active1002 fddi-default active1003 token-ring-default active1004 fddinet-default active1005 trnet-default active
Configuring VLAN Trunking ProtocolPerform this task to configure the VLAN Trunking Protocol (VTP) on an EtherSwitch network module.
VTP Mode Behavior
When a router with an EtherSwitch network module installed is in VTP server mode, you can change the VLAN configuration and have it propagate throughout the network.
When the router is in VTP client mode, you cannot change the VLAN configuration on the device. The client device receives VTP updates from a VTP server in the management domain and modifies its configuration accordingly.
When you configure the router as VTP transparent, you disable VTP on the device. A VTP transparent device does not send VTP updates and does not act on VTP updates received from other devices. However, a VTP transparent device running VTP version 2 does forward received VTP advertisements out all of its trunk links.
SUMMARY STEPS
1. enable
2. vlan database
3. vtp server
4. vtp domain domain-name
5. vtp password password-value
6. vtp client
7. vtp transparent
8. vtp v2-mode
9. exit
10. show vtp {counters | status}
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DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 vlan database
Example:Router# vlan database
Enters VLAN configuration mode.
Step 3 vlan server
Example:Router(vlan)# vlan server
Configures the EtherSwitch network module as a VTP server.
Step 4 vtp domain domain-name
Example:Router(vlan)# vtp domain Lab_Network
Defines the VTP domain name.
• The domain-name argument consists of up to 32 characters.
Step 5 vtp password password-value
Example:Router(vlan)# vtp password labpassword
(Optional) Sets a password for the VTP domain.
• The password-value argument can consist of 8 to 64 characters.
Step 6 vtp client
Example:Router(vlan)# vtp client
(Optional) Configures the EtherSwitch network module as a VTP client.
• The VLAN database is updated when you leave VLAN configuration mode.
Note You would configure the device as either a VTP server or a VTP client.
Step 7 vtp transparent
Example:Router(vlan)# vtp transparent
(Optional) Disables VTP on the EtherSwitch network module.
Step 8 vtp v2-mode
Example:Router(vlan)# vtp v2-mode
(Optional) Enables VTP version 2.
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Examples
Sample Output for the show vtp Command
In the following example, output information about the VTP management domain is displayed:
Router# show vtp status
VTP Version : 2Configuration Revision : 247Maximum VLANs supported locally : 1005Number of existing VLANs : 33VTP Operating Mode : ClientVTP Domain Name : Lab_NetworkVTP Pruning Mode : EnabledVTP V2 Mode : DisabledVTP Traps Generation : DisabledMD5 digest : 0x45 0x52 0xB6 0xFD 0x63 0xC8 0x49 0x80Configuration last modified by 0.0.0.0 at 8-12-99 15:04:49
Configuring Spanning Tree on a VLANPerform this task to enable spanning tree on a per-VLAN basis and configure various spanning tree features. The EtherSwitch network module maintains a separate instance of spanning tree for each VLAN (except on VLANs on which you disable spanning tree).
VLAN Root Bridge
The EtherSwitch network module maintains a separate instance of spanning tree for each active VLAN configured on the device. A bridge ID, consisting of the bridge priority and the bridge MAC address, is associated with each instance. For each VLAN, the switch with the lowest bridge ID will become the root bridge for that VLAN.
To configure a VLAN instance to become the root bridge, the bridge priority can be modified from the default value (32768) to a significantly lower value so that the bridge becomes the root bridge for the specified VLAN. Use the spanning-tree vlan vlan-id root command to alter the bridge priority.
The switch checks the bridge priority of the current root bridges for each VLAN. The bridge priority for the specified VLANs is set to 8192 if this value will cause the switch to become the root for the specified VLANs.
Step 9 exit
Example:Router(vlan)# exit
Exits VLAN configuration mode and returns the router to global configuration mode.
Step 10 show vtp {counters | status}
Example:Router# show vtp status
(Optional) Displays VTP information.
• The optional counters keyword displays the VTP counters for the EtherSwitch network module.
• The optional status keyword displays general information about the VTP management domain.
Command or Action Purpose
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If any root switch for the specified VLANs has a bridge priority lower than 8192, the switch sets the bridge priority for the specified VLANs to 1 less than the lowest bridge priority.
For example, if all switches in the network have the bridge priority for VLAN 100 set to the default value of 32768, entering the spanning-tree vlan 100 root primary command on a switch will set the bridge priority for VLAN 100 to 8192, causing the switch to become the root bridge for VLAN 100.
Note The root bridge for each instance of spanning tree should be a backbone or distribution switch device. Do not configure an access switch device as the spanning tree primary root.
Use the diameter keyword to specify the Layer 2 network diameter (that is, the maximum number of bridge hops between any two end stations in the Layer 2 network). When you specify the network diameter, the switch automatically picks an optimal hello time, forward delay time, and maximum age time for a network of that diameter, which can significantly reduce the spanning tree convergence time. You can use the hello-time keyword to override the automatically calculated hello time.
Note You should avoid configuring the hello time, forward delay time, and maximum age time manually after configuring the switch as the root bridge.
VLAN Bridge Priority
Caution Exercise care when using the spanning-tree vlan command with the priority keyword. For most situations spanning-tree vlan with the root primary keywords and the spanning-tree vlan with the root secondary keywords are the preferred commands to modify the bridge priority.
SUMMARY STEPS
1. enable
2. configure terminal
3. spanning-tree vlan vlan-id [forward-time seconds | hello-time seconds | max-age seconds | priority priority | protocol protocol | [root {primary | secondary} [diameter net-diameter] [hello-time seconds]]]]
4. spanning-tree vlan vlan-id [priority priority]
5. spanning-tree vlan vlan-id [root {primary | secondary} [diameter net-diameter] [hello-time seconds]]
6. spanning-tree vlan vlan-id [hello-time seconds]
7. spanning-tree vlan vlan-id [forward-time seconds]
8. spanning-tree vlan vlan-id [max-age seconds]
9. spanning-tree backbonefast
10. interface {ethernet | fastethernet | gigabitethernet} slot/port
11. spanning-tree port-priority port-priority
12. spanning-tree cost cost
13. exit
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DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 spanning-tree vlan vlan-id [forward-time seconds | hello-time seconds | max-age seconds | priority priority | protocol protocol | [root {primary | secondary} [diameter net-diameter] [hello-time seconds]]]]
Example:Router(config)# spanning-tree vlan 200
Configures spanning tree on a per-VLAN basis.
• In this example, spanning tree is enabled on VLAN 200.
• Use the no form of this command to disable spanning tree on the specified VLAN.
Step 4 spanning-tree vlan vlan-id [priority priority]
Example:Router(config)# spanning-tree vlan 200 priority 33792
(Optional) Configures the bridge priority of a VLAN.
• The priority value can be from 1 to 65535.
• Review the “VLAN Bridge Priority” section before using this command.
• Use the no form of this command to restore the defaults.
Step 5 spanning-tree vlan vlan-id [root {primary | secondary} [diameter net-diameter] [hello-time seconds]]
Example:Router(config)# spanning-tree vlan 200 root primary diameter 4
(Optional) Configures the EtherSwitch network module as the root bridge.
• Review the “VLAN Root Bridge” concept before using this command.
Step 6 spanning-tree vlan vlan-id [hello-time seconds]
Example:Router(config)# spanning-tree vlan 200 hello-time 7
(Optional) Configures the hello time of a VLAN.
• The seconds value can be from 1 to 10 seconds.
• In this example, the hello time is set to 7 seconds.
Step 7 spanning-tree vlan vlan-id [forward-time seconds]
Example:Router(config)# spanning-tree vlan 200 forward-time 21
(Optional) Configures the spanning tree forward delay time of a VLAN.
• The seconds value can be from 4 to 30 seconds.
• In this example, the forward delay time is set to 21 seconds.
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Verifying Spanning Tree on a VLANPerform this optional task to verify the spanning tree configuration on a VLAN.
SUMMARY STEPS
1. enable
2. show spanning-tree [bridge-group] [active | backbonefast | blockedports | bridge | brief | inconsistentports | interface interface-type interface-number | pathcost method | root | summary [totals] | uplinkfast | vlan vlan-id]
Step 8 spanning-tree vlan vlan-id [max-age seconds]
Example:Router(config)# spanning-tree vlan 200 max-age 36
(Optional) Configures the maximum aging time of a VLAN.
• The seconds value can be from 6 to 40 seconds.
• In this example, the maximum number of seconds that the information in a BPDU is valid is set to 36 seconds.
Step 9 spanning-tree backbonefast
Example:Router(config)# spanning-tree vlan 200 max-age 36
(Optional) Enables BackboneFast on the EtherSwitch network module.
• Use this command to detect indirect link failures and to start the spanning tree reconfiguration sooner.
Note If you use BackboneFast, you must enable it on all switch devices in the network. BackboneFast is not supported on Token Ring VLANs but it is supported for use with third-party switches.
Step 10 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface fastethernet 5/8
Selects the Ethernet interface to configure and enters interface configuration mode.
• The slot/port argument identifies the slot and port numbers of the interface. The space between the interface name and number is optional.
Step 11 spanning-tree port-priority port-priority
Example:Router(config-if)# spanning-tree port-priority 64
(Optional) Configures the port priority for an interface.
• The port-priority value can be from 1 to 255 in increments of 4.
Step 12 spanning-tree cost cost
Example:Router(config-if)# spanning-tree cost 18
(Optional) Configures the port cost for an interface.
• The cost value can be from 1 to 200000000 (1 to 65535 in Cisco IOS Releases 12.1(2)E and earlier).
Step 13 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
Command or Action Purpose
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DETAILED STEPS
Step 1 enable
Enables privileged EXEC mode. Enter your password if prompted:
Router> enable
Step 2 show spanning-tree [bridge-group] [active | backbonefast | blockedports | bridge | brief | inconsistentports | interface interface-type interface-number | pathcost method | root | summary [totals] | uplinkfast | vlan vlan-id]
Use this command with the vlan keyword to display spanning tree information about a specified VLAN:
Router# show spanning-tree vlan 200
VLAN200 is executing the ieee compatible Spanning Tree protocol Bridge Identifier has priority 32768, address 0050.3e8d.6401 Configured hello time 2, max age 20, forward delay 15 Current root has priority 16384, address 0060.704c.7000 Root port is 264 (FastEthernet5/8), cost of root path is 38 Topology change flag not set, detected flag not set Number of topology changes 0 last change occurred 01:53:48 ago Times: hold 1, topology change 24, notification 2 hello 2, max age 14, forward delay 10 Timers: hello 0, topology change 0, notification 0
Port 264 (FastEthernet5/8) of VLAN200 is forwarding Port path cost 19, Port priority 128, Port Identifier 129.9. Designated root has priority 16384, address 0060.704c.7000 Designated bridge has priority 32768, address 00e0.4fac.b000 Designated port id is 128.2, designated path cost 19 Timers: message age 3, forward delay 0, hold 0 Number of transitions to forwarding state: 1 BPDU: sent 3, received 3417
Use this command with the interface keyword to display spanning tree information about a specified interface:
Router# show spanning-tree interface fastethernet 5/8
Port 264 (FastEthernet5/8) of VLAN200 is forwarding Port path cost 19, Port priority 100, Port Identifier 129.8. Designated root has priority 32768, address 0010.0d40.34c7 Designated bridge has priority 32768, address 0010.0d40.34c7 Designated port id is 128.1, designated path cost 0 Timers: message age 2, forward delay 0, hold 0 Number of transitions to forwarding state: 1 BPDU: sent 0, received 13513
Use this command with the bridge, brief, and vlan keywords to display the bridge priority information:
Router# show spanning-tree bridge brief vlan 200
Hello Max FwdVlan Bridge ID Time Age Delay Protocol---------------- -------------------- ---- ---- ----- --------VLAN200 33792 0050.3e8d.64c8 2 20 15 ieee
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Configuring Layer 2 InterfacesPerform this task to configure a range of interfaces, define a range macro, set the interface speed, set the duplex mode, and add a description for the interface.
Interface Speed and Duplex Mode Guidelines
When configuring an interface speed and duplex mode, note these guidelines:
• If both ends of the line support autonegotiation, Cisco highly recommends the default autonegotiation settings.
• If one interface supports autonegotiation and the other end does not, configure duplex and speed on both interfaces; do not use the auto setting on the supported side.
• Both ends of the line need to be configured to the same setting. For example, both hard-set or both auto-negotiate. Mismatched settings are not supported.
Caution Changing the interface speed and duplex mode configuration might shut down and reenable the interface during the reconfiguration.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface range {vlan vlan-id - vlan-id} | {{ethernet | fastethernet | macro macro-name} slot/interface - interface} [, {{ethernet | fastethernet | macro macro-name} slot/interface - interface}]
4. define interface-range macro-name {vlan vlan-id - vlan-id} | {{ethernet | fastethernet} slot/interface - interface} [, {{ethernet | fastethernet} slot/interface - interface}]
5. interface fastethernet slot/interface
6. speed [10 | 100 | auto]
7. duplex [auto | full | half]
8. description string
9. exit
10. show interfaces fastethernet slot/port
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DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface range {vlan vlan-id - vlan-id} | {{ethernet | fastethernet | macro macro-name} slot/interface - interface}[, {{ethernet | fastethernet | macro macro-name} slot/interface - interface}]
Example:Router(config)# interface range fastethernet 5/1 - 4
Selects the range of interfaces to be configured.
• The space before and after the dash is required. For example, the command interface range fastethernet 1 - 5 is valid; the command interface range fastethernet 1-5 is not valid.
• You can enter one macro or up to five comma-separated ranges.
• Comma-separated ranges can include both VLANs and physical interfaces.
• You are not required to enter spaces before or after the comma.
The interface range command only supports VLAN interfaces that are configured with the interface vlan command.
Step 4 define interface-range macro-name {vlan vlan-id - vlan-id} | {{ethernet | fastethernet} slot/interface - interface} [, {{ethernet | fastethernet} slot/interface - interface}]
Example:Router(config)# define interface-range sales vlan 2 - 5
• Defines the interface range macro and saves it in NVRAM.
• In this example, the interface range macro is named sales and contains VLAN numbers from 2 to 5.
Step 5 interface fastethernet slot/interface
Example:Router(config)# interface fastethernet 1/4
Configures a specific Fast Ethernet interface.
Step 6 speed [10 | 100 | auto]
Example:Router(config-if)# speed 100
Sets the speed for a Fast Ethernet interface.
Note If you set the interface speed to auto on a 10/100-Mbps Ethernet interface, both speed and duplex are autonegotiated.
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Examples
Sample Output for the show interfaces fastethernet Command
In the following example, output information is displayed to verify the speed and duplex mode of a Fast Ethernet interface:
Router# show interfaces fastethernet 1/4
FastEthernet1/4 is up, line protocol is down Hardware is Fast Ethernet, address is 0000.0000.0c89 (bia 0000.0000.0c89) MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Auto-duplex, Auto-speed ARP type: ARPA, ARP Timeout 04:00:00 Last input never, output never, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 input packets with dribble condition detected 3 packets output, 1074 bytes, 0 underruns(0/0/0) 0 output errors, 0 collisions, 5 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out
Step 7 duplex [auto | full | half]
Example:Router(config-if)# duplex full
Sets the duplex mode for an Ethernet or Fast Ethernet interface.
Note If you set the port speed to auto on a 10/100-Mbps Ethernet interface, both speed and duplex are autonegotiated. You cannot change the duplex mode of autonegotiation interfaces.
Step 8 description string
Example:Router(config-if)# description salesgroup1
Adds a description for an interface.
Step 9 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this step one more time to exit global configuration mode.
Step 10 show interfaces fastethernet slot/port
Example:Router# show interfaces fastethernet 1/4
(Optional) Displays information about Fast Ethernet interfaces.
Command or Action Purpose
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Configuring an Ethernet Interface as a Layer 2 TrunkPerform this task to configure an Ethernet interface as a Layer 2 trunk.
Restrictions
Note Ports do not support Dynamic Trunk Protocol (DTP). Ensure that the neighboring switch is set to a mode that will not send DTP traffic.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
4. shutdown
5. switchport mode {access | trunk}
6. switchport trunk {encapsulation dot1q | native vlan | allowed vlan vlan-list}
7. switchport trunk allowed vlan {add | except | none | remove} vlan1[,vlan[,vlan[,...]]
8. no shutdown
9. exit
10. show interfaces fastethernet slot/port {switchport | trunk}
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface fastethernet 5/8
Selects the Ethernet interface to configure.
Step 4 shutdown
Example:Router(config-if)# shutdown
(Optional) Shuts down the interface to prevent traffic flow until configuration is complete.
Note Encapsulation is always dot1q.
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Examples
Sample Output for the show interfaces fastethernet Command
In the following two examples, output information is displayed to verify the configuration of Fast Ethernet interface as a Layer 2 trunk:
Router# show interfaces fastethernet 5/8 switchport
Name: Fa5/8Switchport: EnabledAdministrative Mode: static accessOperational Mode: static accessAdministrative Trunking Encapsulation: dot1qOperational Trunking Encapsulation: nativeNegotiation of Trunking: DisabledAccess Mode VLAN: 1 (default)Trunking Native Mode VLAN: 1 (default)Trunking VLANs Enabled: ALLPruning VLANs Enabled: 2-1001Protected: false
Step 5 switchport mode {access | trunk}
Example:Router(config-if)# switchport mode trunk
Configures the interface type.
• In this example, the interface type is set to be trunk.
Step 6 switchport trunk [encapsulation dot1q | native vlan | allowed vlan vlan-list]
Example:Router(config-if)# switchport trunk native vlan
Specifies the trunk options when the interface is in trunking mode.
• In this example, native VLAN is set for the trunk in 802.1Q trunking mode.
Step 7 switchport trunk allowed vlan {add | except | none | remove} vlan1[,vlan[,vlan[,...]]
Example:Router(config-if)# switchport trunk allowed vlan add 2,3,4,5
(Optional) Configures the list of VLANs allowed on the trunk.
• All VLANs are allowed by default.
• You cannot remove any of the default VLANs from a trunk.
Step 8 no shutdown
Example:Router(config-if)# no shutdown
Activates the interface. (Required only if you shut down the interface.)
Step 9 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this step one more time to exit global configuration mode.
Step 10 show interfaces fastethernet slot/port {switchport | trunk}
Example:Router# show interfaces fastethernet 5/8 switchport
(Optional) Displays information about Fast Ethernet interfaces.
Command or Action Purpose
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Unknown unicast blocked: falseUnknown multicast blocked: falseBroadcast Suppression Level: 100Multicast Suppression Level: 100Unicast Suppression Level: 100Voice VLAN: noneAppliance trust: none
Router# show interfaces fastethernet 5/8 trunk
Port Mode Encapsulation Status Native vlanFa1/15 off 802.1q not-trunking 1Port Vlans allowed on trunkFa1/15 1Port Vlans allowed and active in management domainFa1/15 1Port Vlans in spanning tree forwarding state and not prunedFa1/15 1
Configuring an Ethernet Interface as a Layer 2 AccessPerform this task to configure an Ethernet interface as a Layer 2 access.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
4. shutdown
5. switchport mode {access | trunk}
6. switchport access vlan vlan-id
7. no shutdown
8. exit
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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Configuring Separate Voice and Data VLANsPerform this task to configure separate voice and data VLANs on the EtherSwitch network module.
Separate Voice and Data VLANs
For ease of network administration and increased scalability, network managers can configure the EtherSwitch network module to support Cisco IP phones such that the voice and data traffic reside on separate VLANs. We recommend configuring separate VLANs when you are able to segment the existing IP address space of your branch office.
User priority bits in the 802.1p portion of the 802.1Q standard header are used to provide prioritization in Ethernet switches. This is a vital component in designing Cisco AVVID networks.
The EtherSwitch network module provides the performance and intelligent services of Cisco IOS software for branch office applications. The EtherSwitch network module can identify user applications—such as voice or multicast video—and classify traffic with the appropriate priority levels. QoS policies are enforced using Layer 2 and 3 information such as 802.1p, IP precedence, and DSCP.
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface fastethernet 1/0
Selects the Ethernet interface to configure.
Step 4 shutdown
Example:Router(config-if)# shutdown
(Optional) Shuts down the interface to prevent traffic flow until configuration is complete.
Note Encapsulation is always dot1q.
Step 5 switchport mode {access | trunk}
Example:Router(config-if)# switchport mode access
Configures the interface type.
• In this example, the interface type is set to be Layer 2 access.
Step 6 switchport access vlan vlan
Example:Router(config-if)# switchport access vlan 5
For access ports, specifies the access VLAN.
• In this example, the Layer 2 access VLAN 5 is set.
Step 7 no shutdown
Example:Router(config-if)# no shutdown
Activates the interface. (Required only if you shut down the interface.)
Step 8 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this step one more time to exit global configuration mode.
Command or Action Purpose
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Note Refer to the Cisco AVVID QoS Design Guide for more information on how to implement end-to-end QoS as you deploy Cisco AVVID solutions.
Voice Traffic and Voice VLAN ID (VVID) Using the EtherSwitch Network Module
The EtherSwitch network module can automatically configure voice VLAN. This capability overcomes the management complexity of overlaying a voice topology onto a data network while maintaining the quality of voice traffic. With the automatically configured voice VLAN feature, network administrators can segment phones into separate logical networks, even though the data and voice infrastructure is physically the same. The voice VLAN feature places the phones into their own VLANs without the need for end-user intervention. A user can plug the phone into the switch, and the switch provides the phone with the necessary VLAN information.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
4. switchport mode {access | trunk}
5. switchport voice vlan {vlan-id | dot1p | none | untagged}
6. exit
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface fastethernet 5/1
Selects the Ethernet interface to configure and enters interface configuration mode.
Step 4 switchport mode {access | trunk}
Example:Router(config-if)# switchport mode trunk
Configures the interface type.
• In this example, the interface type is set to trunk mode.
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Configuring a Single Voice and Data VLANPerform this task to configure a Cisco IP phone to send voice and data traffic on the same VLAN on the EtherSwitch network module.
Single Voice and Data VLAN
For network designs with incremental IP telephony deployment, network managers can configure the EtherSwitch network module so that the voice and data traffic coexist on the same subnet. This might be necessary when it is impractical either to allocate an additional IP subnet for IP phones or to divide the existing IP address space into an additional subnet at the remote branch, it might be necessary to use a single IP address space for branch offices. (This is one of the simpler ways to deploy IP telephony.) When this is the case, you must still prioritize voice above data at both Layer 2 and Layer 3.
Layer 3 classification is already handled because the phone sets the type of service (ToS) bits in all media streams to an IP Precedence value of 5. (With Cisco CallManager Release 3.0(5), this marking changed to a Differentiated Services Code Point ([DSCP]) value of EF.) However, to ensure that there is Layer 2 classification for admission to the multiple queues in the branch office switches, the phone must also use the User Priority bits in the Layer 2 802.1p header to provide class of service (CoS) marking. Setting the bits to provide marking can be done by having the switch look for 802.1p headers on the native VLAN.
This configuration approach must address two key considerations:
• Network managers should ensure that existing subnets have enough available IP addresses for the new Cisco IP phones, each of which requires a unique IP address.
• Administering a network with a mix of IP phones and workstations on the same subnet might pose a challenge.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
4. switchport access vlan vlan-id
5. switchport voice vlan {vlan-id | dot1p | none | untagged}
6. exit
Step 5 switchport voice vlan {vlan-id | dot1p | none | untagged}
Example:Router(config-if)# switchport voice vlan 150
Configures the voice port with a VVID that will be used exclusively for voice traffic.
• In this example, VLAN 150 will be used for voice traffic.
Step 6 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this step one more time to exit global configuration mode.
Command or Action Purpose
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DETAILED STEPS
Managing the EtherSwitch network moduleUse this task to perform basic management tasks such as adding a trap manager and assigning IP information on the EtherSwitch network module with the Cisco IOS CLI. You might find this information useful when you configure the EtherSwitch network module for the previous scenarios.
Trap Managers
A trap manager is a management station that receives and processes traps. When you configure a trap manager, community strings for each member switch must be unique. If a member switch has an IP address assigned to it, the management station accesses the switch by using its assigned IP address.
By default, no trap manager is defined, and no traps are issued.
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface fastethernet 5/2
Selects the Ethernet interface to configure and enters interface configuration mode.
Step 4 switchport access vlan vlan-id
Example:Router(config-if)# switchport access vlan 40
Configures the port as an access port and assigns a VLAN.
• The value of vlan-id represents the ID of the VLAN that is sending and receiving untagged traffic on the port. Valid IDs are from 1 to 1001. Leading zeroes are not accepted.
Step 5 switchport voice vlan {vlan-id | dot1p | none | untagged}
Example:Router(config-if)# switchport voice vlan dot1p
Configures the Cisco IP phone to send voice traffic with higher priority (CoS=5 on 802.1Q tag) on the access VLAN. Data traffic (from an attached PC) is sent untagged for lower priority (port default=0).
Step 6 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this step one more time to exit global configuration mode.
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IP Addressing
The recommended configuration for using multiple cables to connect IP phones to the Cisco AVVID network is to use a separate IP subnet and separate VLANs for IP telephony.
IP Information Assigned to the Switch
You can use a BOOTP server to automatically assign IP information to the switch; however, the BOOTP server must be set up in advance with a database of physical MAC addresses and corresponding IP addresses, subnet masks, and default gateway addresses. In addition, the switch must be able to access the BOOTP server through one of its ports. At startup, a switch without an IP address requests the information from the BOOTP server; the requested information is saved in the switch running the configuration file. To ensure that the IP information is saved when the switch is restarted, save the configuration by entering the write memory command in privileged EXEC mode.
You can change the information in these fields. The mask identifies the bits that denote the network number in the IP address. When you use the mask to subnet a network, the mask is then referred to as a subnet mask. The broadcast address is reserved for sending messages to all hosts. The CPU sends traffic to an unknown IP address through the default gateway.
Use of Ethernet Ports to Support Cisco IP Phones with Multiple Ports
You might want to use multiple ports to connect the Cisco IP phones if any of the following conditions apply to your Cisco IP telephony network:
• You are connecting Cisco IP phones that do not have a second Ethernet port for attaching a PC.
• You want to create a physical separation between the voice and data networks.
• You want to provide in-line power easily to the IP phones without having to upgrade the data infrastructure.
You want to limit the number of switches that need Uninterruptible Power Supply (UPS) power.
Domain Name Mapping and DNS Configuration
Each unique IP address can have a host name associated with it. IP defines a hierarchical naming scheme that allows a device to be identified by its location or domain. Domain names are pieced together with periods (.) as the delimiting characters. For example, Cisco Systems is a commercial organization that IP identifies by a com domain name, so its domain name is cisco.com. A specific device in this domain, the FTP system, for example, is identified as ftp.cisco.com.
To track domain names, IP has defined the concept of a domain name server (DNS), the purpose of which is to hold a cache (or database) of names mapped to IP addresses. To map domain names to IP addresses, you must first identify the host names and then specify a name server and enable the DNS, the Internet’s global naming scheme that uniquely identifies network devices.
You can specify a default domain name that the software uses to complete domain name requests. You can specify either a single domain name or a list of domain names. When you specify a domain name, any IP host name without a domain name has that domain name appended to it before being added to the host table.
You can specify up to six hosts that can function as a name server to supply name information for the DNS.
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If your network devices require connectivity with devices in networks for which you do not control name assignment, you can assign device names that uniquely identify your devices within the entire internetwork. The Internet’s global naming scheme, the DNS, accomplishes this task. This service is enabled by default.
ARP Table Management
To communicate with a device (on Ethernet, for example), the software first must determine the 48-bit MAC or local data link address of that device. The process of determining the local data link address from an IP address is called address resolution.
The Address Resolution Protocol (ARP) associates a host IP address with the corresponding media or MAC addresses and VLAN ID. Taking an IP address as input, ARP determines the associated MAC address. Once a MAC address is determined, the IP-MAC address association is stored in an ARP cache for rapid retrieval. Then the IP datagram is encapsulated in a link-layer frame and sent over the network. Encapsulation of IP datagrams and ARP requests and replies on IEEE 802 networks other than Ethernet is specified by the Subnetwork Access Protocol (SNAP). By default, standard Ethernet-style ARP encapsulation (represented by the arpa keyword) is enabled on the IP interface.
When you manually add entries to the ARP Table by using the CLI, you must be aware that these entries do not age and must be manually removed.
SUMMARY STEPS
1. enable
2. configure terminal
3. snmp-server host {hostname | ip-address} [traps | informs] [version {1 | 2c | 3 [auth | noauth | priv]}] community-string [udp-port port] [notification-type] [vrf vrf-name]
4. interface {ethernet | fastethernet | gigabitethernet} slot/port
5. ip address ip-address
6. exit
7. ip default-gateway ip-address
8. exit
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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Configuring Voice PortsPerform this task to instruct the Cisco 7960 IP phone to give voice traffic a higher priority and to forward all traffic through the 802.1Q native VLAN on the EtherSwitch network module. This task also disables inline power to a Cisco 7960 IP phone to allow voice traffic to be forwarded to and from the phone.
The EtherSwitch network module can connect to a Cisco 7960 IP phone and carry IP voice traffic. If necessary, the EtherSwitch network module can supply electrical power to the circuit connecting it to the Cisco 7960 IP phone.
Because the sound quality of an IP telephone call can deteriorate if the data is unevenly transmitted, the current release of the Cisco IOS software supports QoS based on IEEE 802.1p CoS. QoS uses classification and scheduling to transmit network traffic from the switch in a predictable manner.
The Cisco 7960 IP phone contains an integrated three-port 10/100 switch. The ports are dedicated to connect to the following devices:
• Port 1 connects to the EtherSwitch network module switch or other voice-over-IP device
• Port 2 is an internal 10/100 interface that carries the phone traffic
• Port 3 connects to a PC or other device
Step 3 snmp-server host {hostname | ip-address} [traps | informs] [version {1 | 2c | 3 [auth | noauth | priv]}] community-string [udp-port port] [notification-type] [vrf vrf-name]
Example:Router(config)# snmp-server host 10.6.1.1 traps 1 snmp vlan-membership
Enters the trap manager IP address, community string, and the traps to generate.
Step 4 interface vlan vlan-id
Example:Router(config)# interface vlan 200
Enters interface configuration mode, and specifies the VLAN to which the IP information is assigned.
• VLAN 1 is the management VLAN, but you can configure any VLAN from IDs 1 to 1001.
Step 5 ip address ip-address
Example:Router(config-if)# ip address 10.2.1.2
Enters the IP address and subnet mask.
Step 6 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
Step 7 ip default-gateway ip-address
Example:Router(config)# ip default-gateway 10.5.1.5
Enters the IP address of the default routing device.
Step 8 exit
Example:Router(config)# exit
Exits global configuration mode and returns the router to privileged EXEC mode.
Command or Action Purpose
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Port Connection to a Cisco 7960 IP Phone
Because a Cisco 7960 IP phone also supports connection to a PC or other device, a port connecting a EtherSwitch network module to a Cisco 7960 IP phone can carry a mix of traffic. There are three ways to configure a port connected to a Cisco 7960 IP phone:
• All traffic is transmitted according to the default COS priority (0) of the port. This is the default.
• Voice traffic is given a higher priority by the phone, and all traffic is in the same VLAN.
• Voice and data traffic are carried on separate VLANs, and voice traffic always has a CoS priority of 5.
Inline Power on an EtherSwitch Network Module
The EtherSwitch network module can supply inline power to a Cisco 7960 IP phone, if necessary. The Cisco 7960 IP phone can also be connected to an AC power source and supply its own power to the voice circuit. When the Cisco 7960 IP phone is supplying its own power, an EtherSwitch network module can forward IP voice traffic to and from the phone.
A detection mechanism on the EtherSwitch network module determines whether it is connected to a Cisco 7960 IP phone. If the switch senses that there is no power on the circuit, the switch supplies the power. If there is power on the circuit, the switch does not supply it.
You can configure the switch to never supply power to the Cisco 7960 IP phone and to disable the detection mechanism.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
4. switchport voice vlan {vlan-id | dot1p | none | untagged}
5. power inline {auto | never}
6. exit
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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Verifying Cisco Discovery ProtocolPerform this optional task to verify that Cisco Discovery Protocol (CDP) is enabled globally, enabled on an interface, and to display information about neighboring equipment. CDP is enabled by default. For more details on CDP commands refer to the Configuration Fundamentals and Network Management Command Reference, Release 12.3 T.
SUMMARY STEPS
1. enable
2. show cdp
3. show cdp interface [interface-type interface-number]
4. show cdp neighbors [interface-type interface-number] [detail]
DETAILED STEPS
Step 1 enable
Enables privileged EXEC mode. Enter your password if prompted:
Router> enable
Step 2 show cdp
Use this command to verify that CDP is globally enabled:
Router# show cdp
Global CDP information: Sending CDP packets every 120 seconds Sending a holdtime value of 180 seconds Sending CDPv2 advertisements is enabled
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface fastethernet 1/0
Selects the port to configure and enters interface configuration mode.
Step 4 switchport voice vlan {vlan-id | dot1p | none | untagged}
Example:Router(config-if)# switchport voice vlan dot1p
Instructs the EtherSwitch network module to use 802.1p priority tagging for voice traffic and to use VLAN 0 (default native VLAN) to carry all traffic.
Step 5 power inline {auto | never}
Example:Router(config-if)# power inline never
Determine how inline power is applied to the device on the specified port.
• In this example, inline power on the port is permanently disabled.
Step 6 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this step one more time to exit global configuration mode.
Command or Action Purpose
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Step 3 show cdp interface [interface-type interface-number]
Use this command to verify the CDP configuration on an interface:
Router# show cdp interface fastethernet 5/1
FastEthernet5/1 is up, line protocol is up Encapsulation ARPA Sending CDP packets every 120 seconds Holdtime is 180 seconds
Step 4 show cdp neighbors [interface-type interface-number] [detail]
Use this command to verify information about the neighboring equipment:
Router# show cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - RepeaterDevice ID Local Intrfce Holdtme Capability Platform Port IDJAB023807H1 Fas 5/3 127 T S WS-C2948 2/46JAB023807H1 Fas 5/2 127 T S WS-C2948 2/45JAB023807H1 Fas 5/1 127 T S WS-C2948 2/44JAB023807H1 Gig 1/2 122 T S WS-C2948 2/50JAB023807H1 Gig 1/1 122 T S WS-C2948 2/49JAB03130104 Fas 5/8 167 T S WS-C4003 2/47JAB03130104 Fas 5/9 152 T S WS-C4003 2/48
Configuring the MAC Table to Provide Port SecurityPerform this task to enable the MAC address secure option, create a static or dynamic entry in the MAC address table, and configure the aging timer.
Port security is implemented by providing the user with the option to make a port secure by allowing only well-known MAC addresses to send in data traffic.
MAC Addresses and VLANs
The EtherSwitch network module uses the MAC address tables to forward traffic between ports. All MAC addresses in the address tables are associated with one or more ports. These MAC tables include the following types of addresses:
• Dynamic address—a source MAC address that the switch learns and then drops when it is not in use.
• Secure address—a manually entered unicast address that is usually associated with a secured port. Secure addresses do not age.
• Static address—a manually entered unicast or multicast address that does not age and that is not lost when the switch resets.
The address tables list the destination MAC address and the associated VLAN ID, module, and port number associated with the address.
All addresses are associated with a VLAN. An address can exist in more than one VLAN and have different destinations in each. Multicast addresses, for example, could be forwarded to port 1 in VLAN 1 and ports 9, 10, and 11 in VLAN 5.
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Each VLAN maintains its own logical address table. A known address in one VLAN is unknown in another until it is learned or statically associated with a port in the other VLAN. An address can be secure in one VLAN and dynamic in another. Addresses that are statically entered in one VLAN must be static addresses in all other VLANs.
Address Aging Time
Dynamic addresses are source MAC addresses that the switch learns and then drops when they are not in use. Use the Aging Time field to define how long the switch retains unseen addresses in the table. This parameter applies to all VLANs.
Setting too short an aging time can cause addresses to be prematurely removed from the table. Then when the switch receives a packet for an unknown destination, it floods the packet to all ports in the same VLAN as the receiving port. This unnecessary flooding can impact performance. Setting too long an aging time can cause the address table to be filled with unused addresses; it can cause delays in establishing connectivity when a workstation is moved to a new port.
Caution Cisco advises that you do not change the aging timer because the EtherSwitch network module could go out of synchronization.
Secure Addresses
The secure address table contains secure MAC addresses and their associated ports and VLANs. A secure address is a manually entered unicast address that is forwarded to only one port per VLAN. If you enter an address that is already assigned to another port, the switch reassigns the secure address to the new port.
You can enter a secure port address even when the port does not yet belong to a VLAN. When the port is later assigned to a VLAN, packets destined for that address are forwarded to the port.
Static Addresses
A static address has the following characteristics:
• It is manually entered in the address table and must be manually removed.
• It can be a unicast or multicast address.
• It does not age and is retained when the switch restarts.
Because all ports are associated with at least one VLAN, the switch acquires the VLAN ID for the address from the ports that you select on the forwarding map. A static address in one VLAN must be a static address in other VLANs. A packet with a static address that arrives on a VLAN where it has not been statically entered is flooded to all ports and not learned.
SUMMARY STEPS
1. enable
2. configure terminal
3. mac-address-table secure mac-address {fastethernet | gigabitethernet} slot/port vlan vlan-id
4. mac-address-table [dynamic | static ] mac-address {fastethernet | gigabitethernet} slot/port vlan vlan-id
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5. mac-address-table aging-time seconds
6. exit
7. show mac-address-table [aging-time | secure]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 mac-address-table secure mac-address {fastethernet | gigabitethernet} slot/port vlan vlan-id
Example:Router(config)# mac-address-table secure 0003.0003.0003 fastethernet 2/8 vlan 2
Secures the MAC address traffic on the port.
• Use the no form of this command to restore the defaults.
Step 4 mac-address-table [dynamic | static] mac-address {fastethernet | gigabitethernet} slot/port vlan vlan-id
Example:Router(config)# mac-address-table static 0001.6443.6440 fastethernet 2/8 vlan 1
Creates a static or dynamic entry in the MAC address table.
Note Only the port where the link is up will see the dynamic entry validated in the EtherSwitch network module.
Step 5 mac-address-table aging-time seconds
Example:Router(config)# mac-address-table aging-timer 23
Configures the MAC address aging-timer age in seconds.
• Default aging time is 300 seconds.
Step 6 exit
Example:Router(config-if)# exit
Exits global configuration mode and returns the router to privileged EXEC mode.
Step 7 show mac-address-table [aging-time | secure]
Example:Router# show mac-address-table secure
(Optional) Displays information about the MAC address table.
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Examples
Sample Output for the show mac-address-table Command
In the following example, output information is displayed to verify the configuration of the secure port:
Router# show mac-address-table secure
Secure Address Table:Destination Address Address Type VLAN Destination Port------------------- ------------ ---- --------------------0003.0003.0003 Secure 1 FastEthernet 2/8
In the following example, information about static and dynamic addresses in the MAC address table is displayed:
Router# show mac-address-table
Destination Address Address Type VLAN Destination Port------------------- ------------ ---- --------------------0001.6443.6440 Static 1 Vlan10004.c16d.9be1 Dynamic 1 FastEthernet2/130004.ddf0.0282 Dynamic 1 FastEthernet2/130006.0006.0006 Dynamic 1 FastEthernet2/13001b.001b.ad45 Dynamic 1 FastEthernet2/13
In the following example, information about the MAC address aging timer is displayed:
Router# show mac-address-table aging-timer
Mac address aging time 23
Configuring 802.1x AuthenticationPerform the following tasks to configure 802.1x port-based authentication on the EtherSwitch network module:
• Enabling 802.1x Authentication, page 271 (required)
• Configuring the Switch-to-RADIUS-Server Communication, page 273 (optional)
• Configuring 802.1x Parameters (Retransmissions and Timeouts), page 274 (optional)
802.1x Authentication Guidelines for the EtherSwitch network module
These are the 802.1x authentication configuration guidelines:
• When the 802.1x protocol is enabled, ports are authenticated before any other Layer 2 feature is enabled.
• The 802.1x protocol is supported on Layer 2 static-access ports, but it is not supported on these port types:
– Trunk port—If you try to enable 802.1x on a trunk port, an error message appears, and 802.1x is not enabled. If you try to change the mode of an 802.1x-enabled port to trunk, the port mode is not changed.
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– EtherChannel port—Before enabling 802.1x on the port, you must first remove the port from the EtherChannel before enabling 802.1x on it. If you try to enable 802.1x on an EtherChannel or on an active port in an EtherChannel, an error message appears, and 802.1x is not enabled. If you enable 802.1x on a not-yet active port of an EtherChannel, the port does not join the EtherChannel.
Switch Port Analyzer (SPAN) destination port—You can enable 802.1x on a port that is a SPAN destination port; however, 802.1x is disabled until the port is removed as a SPAN destination. You can enable 802.1x on a SPAN source port.
Table 19 shows the default 802.1x configuration.
Table 19 Default 802.1x Configuration
Feature Default Setting
Authentication, authorization, and accounting (AAA)
Disabled.
RADIUS server
• IP address
• UDP authentication port
• Key
• None specified.
• 1645.
• None specified.
Per-interface 802.1x enable state Disabled (force-authorized).
The port transmits and receives normal traffic without 802.1x-based authentication of the client.
Periodic reauthentication Disabled.
Number of seconds between reauthentication attempts
3600 seconds.
Quiet period 60 seconds (number of seconds that the switch remains in the quiet state following a failed authentication exchange with the client).
Retransmission time 30 seconds (number of seconds that the switch should wait for a response to an EAP request/identity frame from the client before retransmitting the request).
Maximum retransmission number 2 times (number of times that the switch will send an EAP-request/identity frame before restarting the authentication process).
Multiple host support Disabled.
Client timeout period 30 seconds (when relaying a request from the authentication server to the client, the amount of time the switch waits for a response before retransmitting the request to the client). This setting is not configurable.
Authentication server timeout period 30 seconds (when relaying a response from the client to the authentication server, the amount of time the switch waits for a reply before retransmitting the response to the server). This setting is not configurable.
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Enabling 802.1x Authentication
To enable 802.1x port-based authentication, you must enable AAA and specify the authentication method list. A method list describes the sequence and authentication methods to be queried to authenticate a user.
The software uses the first method listed to authenticate users; if that method fails to respond, the software selects the next authentication method in the method list. This process continues until there is successful communication with a listed authentication method or until all defined methods are exhausted. If authentication fails at any point in this cycle, the authentication process stops, and no other authentication methods are attempted.
You control the port authorization state by using the dot1x port-control interface configuration command and these keywords:
• force-authorized—disables 802.1x and causes the port to change to the authorized state without any authentication exchange required. The port transmits and receives normal traffic without 802.1x-based authentication of the client. This is the default setting.
• force-unauthorized—causes the port to remain in the unauthorized state, ignoring all attempts by the client to authenticate. The switch cannot provide authentication services to the client through the interface.
• auto—enables 802.1x and causes the port to begin in the unauthorized state, allowing only EAPOL frames to be sent and received through the port. The authentication process begins when the link state of the port changes from down to up, or when an EAPOL-start frame is received. The switch requests the identity of the client and begins relaying authentication messages between the client and the authentication server. Each client attempting to access the network is uniquely identified by the switch by using the client’s MAC address.
To disable AAA, use the no aaa new-model global configuration command. To disable 802.1x AAA authentication, use the no form of the aaa authentication dot1x global configuration command. To disable 802.1x, use the dot1x port-control command with the force-authorized keyword or the no form of the dot1x port-control interface configuration command.
SUMMARY STEPS
1. enable
2. configure terminal
3. aaa new-model
4. aaa authentication dot1x default group radius
5. interface type slot/port
6. dot1x port-control [auto | force-authorized | force-unauthorized]
7. exit
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DETAILED STEPS
Command Description
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 aaa new-model
Example:Router (config)# aaa new-model
Enables AAA.
Step 4 aaa authentication dot1x default group radius
Example:Router (config)# aaa authentication dot1x default group radius
Creates an 802.1x authentication method list.
To create a default list that is used when a named list is not specified in the authentication command, use the default keyword followed by the methods that are to be used in default situations. The default method list is automatically applied to all interfaces.
Enter at least one of these keywords:
• group radius—Use the list of all RADIUS servers for authentication.
• none—Use no authentication. The client is automatically authenticated without the switch using the information supplied by the client.
Step 5 interface type slot/port
Example:Router (config)# interface fastethernet 5/1
Enters interface configuration mode and specifies the interface to be enabled for 802.1x port-based authentication.
Step 6 dot1x port-control [auto | force-authorized | force-unauthorized]
Example:Router (config-if)# dot1x port-control auto
Enables 802.1x port-based authentication on the interface.
For feature interaction information with trunk, dynamic, dynamic-access, EtherChannel, secure, and SPAN ports, see the “802.1x Authentication Guidelines for the EtherSwitch network module” section on page 269.
Step 7 exit
Example:Router(config)# exit
Exits interface configuration mode and returns the router to privileged EXEC mode.
• Repeat this command to exit global configuration mode and return to privileged EXEC mode.
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Configuring the Switch-to-RADIUS-Server Communication
Perform this task to configure RADIUS server parameters.
RADIUS Security Servers
RADIUS security servers are identified by their host name or IP address, host name and specific UDP port numbers, or IP address and specific UDP port numbers. The combination of the IP address and UDP port number creates a unique identifier, which enables RADIUS requests to be sent to multiple UDP ports on a server at the same IP address. If two different host entries on the same RADIUS server are configured for the same service—for example, authentication—the second host entry configured acts as the fail-over backup to the first one. The RADIUS host entries are tried in the order that they were configured.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip radius source-interface interface-name
4. radius-server host {hostname | ip-address} auth-port port-number key string
5. radius-server key string
DETAILED STEPS
Command Description
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip radius source-interface interface-name
Example:Router (config)# ip radius source-interface ethernet1
Forces RADIUS to use the IP address of a specified interface for all outgoing RADIUS packets.
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Configuring 802.1x Parameters (Retransmissions and Timeouts)
Perform this task to configure various 802.1x retransmission and timeout parameters. Because all of these parameters have default values, configuring them is optional.
Note You should change the default values of these commands only to adjust for unusual circumstances such as unreliable links or specific behavioral problems with certain clients and authentication servers.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
Step 4 radius-server host {hostname | ip-address} auth-port port-number key string
Example:Router (config)# radius-server host 172.16.39.46 auth-port 1612 key rad123
Configures the RADIUS server parameters on the switch.
• Use the hostname or ip-address argument to specify the host name or IP address of the remote RADIUS server.
• Use the auth-port port-number keyword and argument to specify the UDP destination port for authentication requests. The default is 1645.
• Use the key string keyword and argument to specify the authentication and encryption key used between the switch and the RADIUS daemon running on the RADIUS server. The key is a text string that must match the encryption key used on the RADIUS server.
Note Always configure the key as the last item in the radius-server host command syntax because leading spaces are ignored, but spaces within and at the end of the key are used. If you use spaces in the key, do not enclose the key in quotation marks unless the quotation marks are part of the key. This key must match the encryption used on the RADIUS daemon.
• To use multiple RADIUS servers, repeat this command for each server.
Step 5 radius-server key string
Example:Router (config)# radius-server key radiuskey
Configures the authorization and encryption key used between the router and the RADIUS daemon running on the RADIUS server.
• The key is a text string that must match the encryption key used on the RADIUS server.
Command Description
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4. dot1x port-control [auto | force-authorized | force-unauthorized]
5. dot1x multiple-hosts
6. exit
7. dot1x max-req number-of-retries
8. dot1x re-authentication
9. dot1x timeout tx-period value
10. dot1x timeout re-authperiod value
11. dot1x timeout quiet-period value
12. dot1x default
13. exit
14. show dot1x [statistics] [interface interface-type interface-number]
DETAILED STEPS
Command Description
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface fastethernet 5/6
Specifies the interface to which multiple hosts are indirectly attached and enters interface configuration mode.
Step 4 dot1x port-control [auto | force-authorized | force-unauthorized]
Example:Router (config-if)# dot1x port-control auto
Enables 802.1x port-based authentication on the interface.
For feature interaction information with trunk, dynamic, dynamic-access, EtherChannel, secure, and SPAN ports, see the “802.1x Authentication Guidelines for the EtherSwitch network module” section on page 269.
Step 5 dot1x multiple-hosts
Example:Router (config-if)# dot1x multiple-hosts
Allows multiple hosts (clients) on an 802.1x-authorized port.
Note Make sure that the dot1x port-control interface configuration command is set to auto for the specified interface.
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Step 6 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
Step 7 dot1x max-req number-of-retries
Example:Router (config)# dot1x max-req 3
Sets the number of times that the switch sends an EAP-request/identity frame to the client before restarting the authentication process.
• The range is from 1 to 10; the default is 2.
Step 8 dot1x re-authentication
Example:Router (config)# dot1x reauthentication
Enables periodic reauthentication of the client, which is disabled by default.
• The reauthentication period can be set using the dot1x timeout command.
Step 9 dot1x timeout re-authperiod value
Example:Router (config)# dot1x timeout re-authperiod 1800
Sets the number of seconds between reauthentication attempts.
• The range is from 1 to 4294967295; the default is 3600 seconds.
Note This command affects the behavior of the switch only if periodic reauthentication is enabled.
Step 10 dot1x timeout tx-period value
Example:Router (config)# dot1x timeout tx-period 60
Sets the number of seconds that the EtherSwitch network module waits for a response to an EAP-request/identity frame from the client before retransmitting the request.
• The range is from 1 to 65535 seconds; the default is 30.
Step 11 dot1x timeout quiet-period value
Example:Router (config)# dot1x timeout quiet-period 600
Sets the number of seconds that the EtherSwitch network module remains in a quiet state following a failed authentication exchange with the client.
• The range is from 1 to 65535 seconds; the default is 60.
Step 12 dot1x default
Example:Router (config)# dot1x default
Resets the configurable 802.1x parameters to the default values.
Step 13 exit
Example:Router(config)# exit
Exits global configuration mode and returns the router to privileged EXEC mode.
Step 14 show dot1x [statistics] [interface interface-type interface-number]
Example:Router# show dot1x statistics interface fastethernet 0/1
(Optional) Displays 802.1x statistics, administrative status, and operational status for the EtherSwitch network module or a specified interface.
Command Description
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Examples
Sample Output for the show dot1x Command
In the following example, statistics appear for all the physical ports for the specified interface:
Router# show dot1x statistics fastethernet 0/1
FastEthernet0/1
Rx: EAPOL EAPOL EAPOL EAPOL EAP EAP EAP Start Logoff Invalid Total Resp/Id Resp/Oth LenError 0 0 0 21 0 0 0
Last Last EAPOLVer EAPOLSrc 1 0002.4b29.2a03
Tx: EAPOL EAP EAP Total Req/Id Req/Oth 622 445 0
In the following example, global 802.1x parameters and a summary are displayed:
Router# show dot1x
Global 802.1X Parameters reauth-enabled no reauth-period 3600 quiet-period 60 tx-period 30 supp-timeout 30 server-timeout 30 reauth-max 2 max-req 2
802.1X Port Summary Port Name Status Mode Authorized Gi0/1 disabled n/a n/a Gi0/2 enabled Auto (negotiate) no
802.1X Port Details 802.1X is disabled on GigabitEthernet0/1802.1X is enabled on GigabitEthernet0/2 Status Unauthorized Port-control Auto Supplicant 0060.b0f8.fbfb Multiple Hosts Disallowed Current Identifier 2
Authenticator State Machine State AUTHENTICATING Reauth Count 1
Backend State Machine State RESPONSE Request Count 0 Identifier (Server) 2
Reauthentication State Machine State INITIALIZE
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Configuring Power Management on the InterfacesPerform this task to manage the powering of the Cisco IP phones.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
4. power inline {auto | never}
5. exit
6. show power inline
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface fastethernet 5/6
Selects the Ethernet interface to configure and enters interface configuration mode.
Step 4 power inline {auto | never}
Example:Router(config-if)# power inline auto
Configures the port to supply inline power automatically to a Cisco IP phone.
• Use the never keyword to permanently disable inline power on the port.
Step 5 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this command to exit global configuration mode and return to privileged EXEC mode.
Step 6 show power inline
Example:Router# show power inline
(Optional) Displays information about the power configuration on the ports.
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Examples
Sample Output for the show power inline Command
In the following example, output information is displayed to verify the power configuration on the ports:
Router# show power inline
PowerSupply SlotNum. Maximum Allocated Status----------- -------- ------- --------- ------ EXT-PS 1 165.000 20.000 PS1 GOOD PS2 ABSENT
Interface Config Phone Powered PowerAllocated--------- ------ ----- ------- --------------FastEthernet1/0 auto no off 0.000 WattsFastEthernet1/1 auto no off 0.000 WattsFastEthernet1/2 auto no off 0.000 WattsFastEthernet1/3 auto no off 0.000 WattsFastEthernet1/4 auto unknown off 0.000 WattsFastEthernet1/5 auto unknown off 0.000 WattsFastEthernet1/6 auto unknown off 0.000 WattsFastEthernet1/7 auto unknown off 0.000 WattsFastEthernet1/8 auto unknown off 0.000 WattsFastEthernet1/9 auto unknown off 0.000 WattsFastEthernet1/10 auto unknown off 0.000 WattsFastEthernet1/11 auto yes on 6.400 WattsFastEthernet1/12 auto yes on 6.400 WattsFastEthernet1/13 auto no off 0.000 WattsFastEthernet1/14 auto unknown off 0.000 WattsFastEthernet1/15 auto unknown off 0.000 Watts
Configuring Storm ControlThis section consists of two tasks. The first task enables global storm control, and the second task configures storm control on a per-port basis.
• Enabling Global Storm Control, page 279
• Enabling Per-Port Storm Control, page 281
Enabling Global Storm Control
Perform this task to enable a specified type of global storm control.
SUMMARY STEPS
1. enable
2. configure terminal
3. storm-control {{{broadcast | multicast | unicast} level level [lower-level]} | action shutdown}
4. exit
5. show interface [interface-type interface-number] counters {broadcast | multicast | unicast}
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DETAILED STEPS
Examples
Sample Output for the show interface counters Command
In the following example, output information is displayed to verify the number of packets discarded for the specified storm control suppression:
Router# show interface counters broadcast
Port BcastSuppDiscardsFa0/1 0Fa0/2 0
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 storm-control {{{broadcast | multicast | unicast} level level [lower-level]}| action shutdown}
Example:Router(config)# storm-control broadcast level 75
Specifies the global broadcast, multicast, or unicast storm control suppression level as a percentage of total bandwidth.
• A threshold value of 100 percent means that no limit is placed on the specified type of traffic.
• Use the level keyword and argument to specify the threshold value.
• Use the no form of this command to restore the defaults.
Step 4 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this command to exit global configuration mode and return to privileged EXEC mode.
Step 5 show interface [interface-type interface-number] counters {broadcast | multicast | unicast}
Example:Router# show interface counters broadcast
(Optional) Displays the type of storm control suppression counter currently in use and displays the number of discarded packets.
• Use the interface-type and interface-number arguments to display the type of storm control suppression counter for a specified interface.
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Enabling Per-Port Storm Control
Perform this task to configure storm control on a specified interface.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
4. storm-control {{{broadcast | multicast | unicast} level level [lower-level]} | action shutdown}
5. storm-control action shutdown
6. exit
7. show storm-control [interface-type interface-number] [broadcast | multicast | unicast | history]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface fastethernet 5/6
Selects the Ethernet interface to configure and enters interface configuration mode.
Step 4 storm-control {{{broadcast | multicast | unicast} level level [lower-level]}| action shutdown}
Example:Router(config-if)# storm-control multicast level 80
Configures broadcast, multicast, or unicast per-port storm-control.
• Use the level keyword and argument to specify the rising threshold level for either broadcast, multicast, or unicast traffic. The storm control action occurs when traffic utilization reaches this level.
• Use the optional lower-level argument to specify the falling threshold level. The normal transmission restarts (if the action is filtering) when traffic drops below this level.
• A threshold value of 100 percent means that no limit is placed on the specified type of traffic.
• Use the no form of this command to restore the defaults.
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Examples
Sample Output for the show storm-control Command
In the following example, output information is displayed to verify the number of packets discarded for the specified storm control suppression:
Router# show storm-control broadcast
Interface Filter State Upper Lower Current--------- ------------- ------- ------- -------Fa0/1 <inactive> 100.00% 100.00% 0.00%Fa0/2 <inactive> 100.00% 100.00% 0.00%Fa0/3 <inactive> 100.00% 100.00% 0.00%Fa0/4 Forwarding 30.00% 20.00% 20.32%
Configuring Layer 2 EtherChannels (Port-Channel Logical Interfaces)Perform this task to configure Layer 2 Ethernet interfaces as a Layer 2 EtherChannel, configure EtherChannel load balancing, and remove an Ethernet interface from an EtherChannel.
To configure Layer 2 EtherChannels, configure the Ethernet interfaces with the channel-group command, which creates the port-channel logical interface. You do not have to create a port-channel interface before assigning a physical interface to a channel group. A port-channel interface is created automatically when the channel group gets its first physical interface, if it is not already created.
Restrictions
• Cisco IOS software creates port-channel interfaces for Layer 2 EtherChannels when you configure Layer 2 Ethernet interfaces with the channel-group command. You cannot put Layer 2 Ethernet interfaces into a manually created port-channel interface.
• Layer 2 interfaces must be connected and functioning for Cisco IOS software to create port-channel interfaces for Layer 2 EtherChannels.
Step 5 storm-control action shutdown
Example:Router(config-if)# storm-control action shutdown
Selects the shutdown keyword to disable the port during a storm.
• The default is to filter out the traffic
• Use the no keyword to restore the defaults.
Step 6 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this command to exit global configuration mode and return to privileged EXEC mode.
Step 7 show storm-control [interface-type interface-number] [broadcast | multicast | unicast | history]
Example:Router# show storm-control broadcast
(Optional) Displays the type of storm control suppression for all interfaces on the EtherSwitch network module.
• Use the interface-type and interface-number arguments to display the type of storm control suppression for a specified interface.
Command or Action Purpose
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SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
4. channel-group port-channel-number mode on
5. Repeat Steps 3 through 4 for each Ethernet interface to be added as a Layer 2 EtherChannel.
6. exit
7. port-channel load-balance {src-mac | dst-mac | src-dst-mac | src-ip | dst-ip | src-dst-ip}
8. no interface port-channel port-channel-number
9. exit
10. show interfaces fastethernet slot/port {etherchannel | switchport | trunk}
11. show etherchannel [channel-group] {port-channel | brief | detail | summary | port | load-balance}
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface fastethernet 5/6
Selects the Ethernet interface to configure.
Step 4 channel-group port-channel-number mode on
Example:Router(config)# channel-group 2 mode on
Configures the interface in a port-channel.
• In this example, the Etherchannel group 2 is configured.
Step 5 Repeat Steps 3 through 4 for each Ethernet interface to be added as a Layer 2 EtherChannel.
—
Step 6 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
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Examples
Sample Output for the show interfaces fastethernet Command
In the following example, output information is displayed to verify the configuration of Fast Ethernet interface as a Layer 2 EtherChannel:
Router# show interfaces fastethernet 5/6 etherchannel
Port state = EC-Enbld Up In-Bndl Usr-Config
Channel group = 2 Mode = Desirable Gcchange = 0Port-channel = Po2 GC = 0x00020001Port indx = 1 Load = 0x55 Flags: S - Device is sending Slow hello. C - Device is in Consistent state. A - Device is in Auto mode. P - Device learns on physical port.Timers: H - Hello timer is running. Q - Quit timer is running. S - Switching timer is running. I - Interface timer is running.Local information: Hello Partner PAgP Learning GroupPort Flags State Timers Interval Count Priority Method IfindexFa5/6 SC U6/S7 30s 1 128 Any 56 Partner’s information:
Step 7 port-channel load-balance {src-mac | dst-mac | src-dst-mac | src-ip | dst-ip | src-dst-ip}
Example:Router(config)# port-channel load-balancing src-mac
Configures EtherChannel load balancing.
• In this example, the load balancing is based on the source MAC addresses.
Step 8 no interface port-channel port-channel-number
Example:Router(config)# no interface port-channel 3
Removes a port channel interface.
• In this example, the interface port channel 3 is removed.
Step 9 exit
Example:Router(config)# exit
Exits global configuration mode and returns the router to privileged EXEC mode.
Step 10 show interfaces fastethernet slot/port {etherchannel | switchport | trunk}
Example:Router# show interfaces fastethernet 5/6 etherchannel
(Optional) Displays information about Fast Ethernet interfaces.
• In this example, EtherChannel information is shown for the specified interface.
Step 11 show etherchannel [channel-group] {port-channel | brief | detail | summary | port | load-balance}
Example:Router# show etherchannel 2 port-channel
(Optional) Displays information about port channels for EtherChannel groups.
Command or Action Purpose
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Partner Partner Partner Partner GroupPort Name Device ID Port Age Flags Cap.Fa5/6 JAB031301 0050.0f10.230c 2/47 18s SAC 2F Age of the port in the current state: 00h:10m:57s
Sample Output for the show etherchannel Command
In the following example, output information about port channels for EtherChannel group 2 is displayed:
Router# show etherchannel 2 port-channel
Port-channels in the group: ---------------------- Port-channel: Po2------------ Age of the Port-channel = 00h:23m:33sLogical slot/port = 10/2 Number of ports in agport = 2GC = 0x00020001 HotStandBy port = nullPort state = Port-channel Ag-Inuse Ports in the Port-channel: Index Load Port------------------- 1 55 Fa5/6 0 AA Fa5/7 Time since last port bundled: 00h:23m:33s Fa5/6
Configuring Flow Control on Gigabit Ethernet PortsPerform this task to configure flow control on a Gigabit Ethernet port.
SUMMARY STEPS
1. enable
2. set port flowcontrol {receive | send} [mod-number/port-number] {off | on | desired}
3. show port flowcontrol
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DETAILED STEPS
Examples
Sample Output for the show port flowcontrol Command
In the following example, output information is displayed to verify the flow control configuration on Gigabit Ethernet ports:
Router# show interfaces fastethernet 5/6 etherchannel
Port Send-Flowcontrol Receive-Flowcntl RxPause TxPause Admin Oper Admin Oper----- ---------------- ---------------- ------- ------ 5/1 off off on disagree 0 0 5/2 off off off off 0 0 5/3 desired on desired off 10 10
Configuring Intrachassis StackingPerform this task to extend Layer 2 switching in the router by connecting the Gigabit Ethernet ports of the EtherSwitch network module.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface gigabitethernet slot/port
4. switchport stacking-partner interface gigabit slot/port
5. exit
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 set port flowcontrol {receive | send} [mod-number/port-number] {off | on | desired}
Example:Router# set port flowcontrol 5/1 receive on
Sets the flow control parameters on a Gigabit Ethernet port.
Step 3 show port flowcontrol
Example:Router# show port flowcontrol
(Optional) Displays information about the flow control for Gigabit Ethernet ports.
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DETAILED STEPS
Configuring Switched Port Analyzer (SPAN)Perform this task to configure the source and destination for a SPAN session.
SUMMARY STEPS
1. enable
2. configure terminal
3. monitor session session-number {source interface interface-type slot/port | vlan vlan-id} [, | - | rx | tx | both]
4. monitor session session-number {destination interface interface-type slot/port [, | - ] | vlan vlan-id}
5. exit
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface gigabitethernet slot/port
Example:Router(config)# interface gigabitethernet 2/0
Selects the Gigabit Ethernet interface to configure.
Step 4 switchport stacking-partner interface gigabitethernet slot/port
Example:Router(config-if)# switchport stacking-link interface gigabitethernet 3/0
Creates the intrachassis stacking between the current Gigabit Ethernet (GE) interface and the stacking link partner GE interface.
• In this example, GE interface 2/0 is stacked on GE interface 3/0 to form an extended VLAN within one chassis on the router.
Step 5 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this command to exit global configuration mode and return to privileged EXEC mode.
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DETAILED STEPS
Configuring Layer 3 InterfacesPerform this task to configure a Layer 3 interface on the EtherSwitch network module. A physical interface on the EtherSwitch network module is configured as a Layer 3 interface and an IP address is assigned to the interface.
Layer 3 Interface Support for the EtherSwitch network module
The EtherSwitch network module supports two types of Layer 3 interfaces for routing and bridging:
• SVIs: You should configure SVIs for any VLANs for which you want to route traffic. SVIs are created when you enter a VLAN ID following the interface vlan global configuration command. To delete an SVI, use the no interface vlan global configuration command.
• Routed ports: Routed ports are physical ports configured to be in Layer 3 mode by using the no switchport interface configuration command.
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 monitor session session-number {source interface interface-type slot/port | vlan vlan-id} [, | - | rx | tx | both]
Example:Router(config)# monitor session 1 source interface fastethernet 5/1 both
Specifies the SPAN session number, the source interface, or VLAN, and the traffic direction to be monitored.
Note Multiple SPAN sessions can be configured, but only one SPAN session is supported at a time.
Step 4 monitor session session-number {destination interface interface-type slot/port [, | -] | vlan vlan-id}
Example:Router(config)# monitor session 1 destination interface fastethernet 5/48
Specifies the SPAN session number, the destination interface, or VLAN.
Step 5 exit
Example:Router(config)# exit
Exits global configuration mode and returns the router to privileged EXEC mode.
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Note A Layer 3 switch can have an IP address assigned to each routed port and SVI. The number of routed ports and SVIs that you can configure is not limited by software; however, the interrelationship between this number and the number of other features being configured might have an impact on CPU utilization because of hardware limitations.
All Layer 3 interfaces require an IP address to route traffic (a routed port cannot obtain an IP address from a DHCP server, but the router can act as a DHCP server and serve IP addresses through a routed port).
Routed ports support only CEF switching (IP fast switching is not supported).
Note If the physical port is in Layer 2 mode (the default), you must enter the no switchport interface configuration command to put the interface into Layer 3 mode. Entering a no switchport command disables and then reenables the interface, which might generate messages on the device to which the interface is connected. When you use this command to put the interface into Layer 3 mode, you are also deleting any Layer 2 characteristics configured on the interface. (Also, when you return the interface to Layer 2 mode, you are deleting any Layer 3 characteristics configured on the interface.)
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
4. no switchport
5. ip address ip-address mask
6. no shutdown
7. exit
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface gigabitethernet 0/10
Selects the Ethernet interface to configure.
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Enabling and Verifying IP Multicast Layer 3 SwitchingPerform this task to enable IP multicast routing globally, enable IP Protocol Independent Multicast (PIM) on a Layer 3 interface, and verify the IP multicast Layer 3 switching information.
You must enable IP multicast routing globally before enabling IP multicast Layer 3 switching on Layer 3 interfaces. Enable PIM on Layer 3 interfaces before adding IP multicast Layer 3 switching functions on those interfaces.
For complete IP multicast command reference information and configuration details, refer to the following documents:
• Cisco IOS IP Configuration Guide
• Cisco IOS IP Command Reference, Volume 3 of 3: Multicast, Release 12.3 T
SUMMARY STEPS
1. enable
2. configure terminal
3. ip multicast-routing
4. interface vlan vlan-id
5. ip pim {dense-mode | sparse-mode | sparse-dense-mode}
6. exit
7. show ip pim [vrf vrf-name] interface [interface-type interface-number] [df | count] [rp-address] [detail]
8. show ip mroute [vrf vrf-name] [group-address | group-name] [source-address | source-name] [interface-type interface-number] [summary] [count] [active kbps]
Step 4 no switchport
Example:Router(config-if)# no switchport
Disables switching on the port and enables routing (Layer 3) mode for physical ports only.
• In this example, Gigabit Ethernet interface 0/10 is now a routed port instead of a switching port.
Step 5 ip address ip-address mask
Example:Router(config)# ip address 10.1.2.3 255.255.0.0
Configures an IP address and subnet.
Step 6 no shutdown
Example:Router(config-if)# no shutdown
Activates the interface. (Required only if you shut down the interface.)
Step 7 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this command to exit global configuration mode and return to privileged EXEC mode.
Command or Action Purpose
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DETAILED STEPS
Examples
Sample Output for the show ip pim Command
In the following example, output information is displayed to verify the IP multicast Layer 3 switching information for an IP PIM Layer 3 interface:
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip multicast-routing
Example:Router(config)# ip multicast-routing
Enables IP multicast routing globally.
Step 4 interface vlan vlan-id
Example:Router(config)# interface vlan 10
Selects the interface to configure.
Step 5 ip pim {dense-mode | sparse-mode | sparse-dense-mode}
Example:Router(config-if)# ip pim sparse-mode
Enables IP PIM on a Layer 3 interface.
Step 6 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this command to exit global configuration mode and return to privileged EXEC mode.
Step 7 show ip pim [vrf vrf-name] interface [interface-type interface-number] [df | count] [rp-address] [detail]
Example:Router# show ip pim interface count
Verifies the IP multicast Layer 3 switching enable state on IP PIM interfaces.
• Use the count keyword to display the number of packets received and sent on the interface.
Step 8 show ip mroute [vrf vrf-name] [group-address | group-name] [source-address | source-name] [interface-type interface-number] [summary] [count] [active kbps]
Example:Router# show ip mroute count
Displays the contents of the IP multicast routing (mroute) table.
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Router# show ip pim interface count
State:* - Fast Switched, D - Distributed Fast SwitchedH - Hardware Switching Enabled
Address Interface FS Mpackets In/Out10.15.1.20 GigabitEthernet4/8 * H 952/423713077010.20.1.7 GigabitEthernet4/9 * H 1385673757/3410.25.1.7 GigabitEthernet4/10* H 0/3410.11.1.30 FastEthernet6/26 * H 0/010.37.1.1 FastEthernet6/37 * H 0/010.22.33.44 FastEthernet6/47 * H 514/68
Sample Output for the show ip mroute Command
In the following example, output information is displayed for the IP multicast routing table:
Router# show ip mroute count
IP Multicast Statistics56 routes using 28552 bytes of memory13 groups, 3.30 average sources per groupForwarding Counts:Pkt Count/Pkts per second/Avg Pkt Size/Kilobits per secondOther counts:Total/RPF failed/Other drops(OIF-null, rate-limit etc) Group:224.2.136.89, Source count:1, Group pkt count:29051 Source:172.206.72.28/32, Forwarding:29051/-278/1186/0, Other:85724/8/56665
Note The negative counter means that the outgoing interface list of the corresponding entry is NULL, and this indicates that this flow is still active.
Configuring IGMP SnoopingPerform this task to enable IGMP snooping on a router with the Ethernet switching network module installed.
IGMP Snooping on the EtherSwitch Network Module
By default, IGMP snooping is globally enabled on the EtherSwitch network module. When globally enabled or disabled, it is also enabled or disabled in all existing VLAN interfaces. By default, IGMP snooping is enabled on all VLANs, but it can be enabled and disabled on a per-VLAN basis.
Global IGMP snooping overrides the per-VLAN IGMP snooping capability. If global snooping is disabled, you cannot enable VLAN snooping. If global snooping is enabled, you can enable or disable snooping on a VLAN basis.
IGMP Immediate-Leave Processing
When you enable IGMP Immediate-Leave processing, the EtherSwitch network module immediately removes a port from the IP multicast group when it detects an IGMP version 2 leave message on that port. Immediate-Leave processing allows the switch to remove an interface that sends a leave message from the forwarding table without first sending out group-specific queries to the interface. You should use the Immediate-Leave feature only when there is only a single receiver present on every port in the VLAN.
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Static Configuration of an Interface to Join a Multicast Group
Ports normally join multicast groups through the IGMP report message, but you can also statically configure a host on an interface.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip igmp snooping
4. ip igmp snooping vlan vlan-id
5. ip igmp snooping vlan vlan-id immediate-leave
6. ip igmp snooping vlan vlan-id static mac-address interface interface-type slot/port
7. ip igmp snooping vlan vlan-id mrouter {interface interface-type slot/port | learn pim-dvmrp}
8. exit
9. show ip igmp snooping [vlan vlan-id]
10. show ip igmp snooping mrouter [vlan vlan-id]
11. show mac-address-table multicast [vlan vlan-id] [user | igmp-snooping] [count]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip igmp snooping
Example:Router(config)# ip igmp snooping
Globally enables IGMP snooping on all existing VLAN interfaces.
Step 4 ip igmp snooping vlan vlan-id
Example:Router(config)# ip igmp snooping vlan 10
Enables IGMP snooping on the specified VLAN interface.
Step 5 ip igmp snooping vlan vlan-id immediate-leave
Example:Router(config)# ip igmp snooping vlan 10 immediate-leave
Enables IGMP Immediate-Leave processing on the specified VLAN interface.
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Configuring Fallback BridgingThis section contains the following tasks to help you configure fallback bridging.
• Configuring a Bridge Group, page 295 (required)
• Adjusting Spanning-Tree Parameters, page 298 (optional)
• Disabling the Spanning Tree on an Interface, page 300 (optional)
Step 6 ip igmp snooping vlan vlan-id static mac-address interface interface-type slot/port
Example:Router(config)# ip igmp snooping vlan 10 static 303.303.303.303 interface fastethernet 1/5
Statically configures a port as a member of a multicast group:
• Use the vlan-id argument to specify the multicast group VLAN ID.
• Use the mac-address argument to specify the group MAC address.
• Use the interface-type and slot/port arguments to configure a port as a member of a multicast group.
Step 7 ip igmp snooping vlan vlan-id mrouter {interface interface-type slot/port | learn pim-dvmrp}
Example:Router(config)# ip igmp snooping vlan 10 mrouter interface fastethernet 1/5
Enables a static connection on a multicast router.
• Use the vlan-id argument to specify the multicast group VLAN ID.
• Use the interface-type and slot/port arguments to specify the interface that connects to the multicast router.
Step 8 exit
Example:Router(config-if)# exit
Exits global configuration mode and returns the router to privileged EXEC mode.
Step 9 show ip igmp snooping [vlan vlan-id]
Example:Router# show ip igmp snooping vlan 10
Displays the IGMP snooping configuration.
• Use the vlan-id argument to specify the multicast group VLAN ID.
Step 10 show ip igmp snooping mrouter [vlan vlan-id]
Example:Router# show ip igmp snooping mrouter vlan 10
Displays information on dynamically learned and manually configured multicast router interfaces.
Step 11 show mac-address-table multicast [vlan vlan-id] [user | igmp-snooping] [count]
Example:Router# show mac-address-table multicast vlan 10 igmp-snooping
Displays MAC address table entries for a VLAN.
• Use the vlan-id argument to specify the multicast group VLAN ID.
• Use the user keyword to display only the user-configured multicast entries.
• Use the igmp-snooping keyword to display entries learned via IGMP snooping.
• Use the count keyword to display only the total number of entries for the selected criteria, not the actual entries.
Command or Action Purpose
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Understanding the Default Fallback Bridging Configuration
Table 20 shows the default fallback bridging configuration.
Configuring a Bridge Group
Perform this task to create a bridge group, filter frames using a specific MAC address, prevent the forwarding of frames for stations that the switching device has dynamically learned, and remove dynamic entries from the bridge table.
Bridge Group Creation
To configure fallback bridging for a set of SVIs or routed ports, these interfaces must be assigned to bridge groups. All interfaces in the same group belong to the same bridge domain. Each SVI or routed port can be assigned to only one bridge group. A maximum of 31 bridge groups can be configured on the switch.
Note The protected port feature is not compatible with fallback bridging. When fallback bridging is enabled, it is possible for packets to be forwarded from one protected port on a switch to another protected port on the same switch if the ports are in different VLANs.
Forwarding of Dynamically Learned Stations
By default, the switch forwards any frames for stations that it has dynamically learned. By disabling this activity, the switch only forwards frames whose addresses have been statically configured into the forwarding cache.
Table 20 Default Fallback Bridging Configuration
Feature Default Setting
Bridge groups None are defined or assigned to an interface. No VLAN-bridge STP is defined.
Switch forwards frames for stations that it has dynamically learned
Enabled.
Bridge table aging time for dynamic entries 300 seconds.
MAC-layer frame filtering Disabled.
Spanning tree parameters:
• Switch priority
• Interface priority
• Interface path cost
• Hello BPDU interval
• Forward-delay interval
• Maximum idle interval
• 32768.
• 128.
• 10 Mbps: 100.100 Mbps: 19.1000 Mbps: 4.
• 2 seconds.
• 20 seconds.
• 30 seconds.
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Bridge Table Aging Time
A switch forwards, floods, or drops packets based on the bridge table. The bridge table maintains both static and dynamic entries. Static entries are entered by you or learned by the switch. Dynamic entries are entered by the bridge learning process. A dynamic entry is automatically removed after a specified length of time, known as aging time, from the time the entry was created or last updated.
If you are likely to move hosts on a switched network, decrease the aging-time to enable the switch to quickly adapt to the change. If hosts on a switched network do not continuously send packets, increase the aging time to keep the dynamic entries for a longer time and thus reduce the possibility of flooding when the hosts send again.
SUMMARY STEPS
1. enable
2. configure terminal
3. bridge bridge-group protocol vlan-bridge
4. interface {ethernet | fastethernet | gigabitethernet} slot/port
5. bridge-group bridge-group
6. exit
7. bridge bridge-group address mac-address {forward | discard} [interface-type interface-number]
8. no bridge bridge-group acquire
9. bridge bridge-group aging-time seconds
10. exit
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 bridge bridge-group protocol vlan-bridge
Example:Router(config)# bridge 10 protocol vlan-bridge
Assigns a bridge group number, and specifies the VLAN-bridge spanning-tree protocol to run in the bridge group.
• Use the bridge-group argument to specify the bridge group number. The range is 1 to 255. You can create up to 31 bridge groups.
Note Frames are bridged only among interfaces in the same group.
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Step 4 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface gigabitethernet 0/1
Selects the Ethernet interface on which the bridge group is assigned and enters interface configuration mode.
The specified interface must be one of the following:
• A routed port: a physical port that you have configured as a Layer 3 port by entering the no switchport interface configuration command.
• An SVI: a VLAN interface that you created by using the interface vlan vlan-id global configuration command.
Note These ports must have IP addresses assigned to them.
Step 5 bridge-group bridge-group
Example:Router(config-if)# bridge-group 10
Assigns the interface to the bridge group created in Step 3.
• By default, the interface is not assigned to any bridge group.
• An interface can be assigned to only one bridge group.
Step 6 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
Step 7 bridge bridge-group address mac-address {forward | discard} [interface-type interface-number]
Example:Router(config)# bridge 1 address 0800.cb00.45e9 forward gigabitethernet 0/1
Specifies the MAC address to discard or forward.
• Use the bridge-group argument to specify the bridge group number. The range is from 1 to 255.
• Use the address mac-address keyword and argument to specify the MAC-layer destination address to be filtered.
• Use the forward keyword if you want the frame destined to the specified interface to be forwarded. Use the discard keyword if you want the frame to be discarded.
• (Optional) Use the interface-type and interface-number arguments to specify the interface on which the address can be reached.
Step 8 no bridge bridge-group acquire
Example:Router(config-if)# no bridge 10 acquire
Stops the EtherSwitch network module from forwarding any frames for stations that it has dynamically learned through the discovery process, and to limit frame forwarding to statically configured stations.
• The switch filters all frames except those whose destined-to addresses have been statically configured into the forwarding cache.
• To configure a static address, use the bridge address global configuration command, see Step 7.
• Use the bridge-group argument to specify the bridge group number. The range is from 1 to 255.
Command or Action Purpose
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Adjusting Spanning-Tree Parameters
Perform this task to adjust spanning tree parameters such as the switch priority or interface priority. You might need to adjust certain spanning-tree parameters if the default values are not suitable for your switch configuration. Parameters affecting the entire spanning tree are configured with variations of the bridge global configuration command. Interface-specific parameters are configured with variations of the bridge-group interface configuration command.
Note Only network administrators with a good understanding of how switches and STP function should make adjustments to spanning-tree parameters. Poorly planned adjustments can have a negative impact on performance. A good source on switching is the IEEE 802.1d specification; for more information, refer to the “References and Recommended Reading” appendix in the Cisco IOS Configuration Fundamentals and Network Management Command Reference, Release 12.3 T.
Switch Priority
You can globally configure the priority of an individual switch when two switches tie for position as the root switch, or you can configure the likelihood that a switch will be selected as the root switch. This priority is determined by default; however, you can change it.
Interface Priority
You can change the priority for an interface. When two switches tie for position as the root switch, you configure an interface priority to break the tie. The switch with the lowest interface value is elected.
Path Cost Assignment
Each interface has a path cost associated with it. By convention, the path cost is 1000/data rate of the attached LAN, in Mbps.
BPDU Intervals Adjustment
You can adjust three different BPDU intervals. The interval between hello BPDUs can be set. The forward-delay interval is the amount of time spent listening for topology change information after an interface has been activated for switching and before forwarding actually begins. The maximum-idle
Step 9 bridge bridge-group aging-time seconds
Example:Router(config-if)# bridge 10 aging-time 200
Specifies the length of time that a dynamic entry remains in the bridge table from the time the entry was created or last updated.
• Use the bridge-group argument to specify the bridge group number. The range is from 1 to 255.
• Use the seconds argument to enter a number from 0 to 1000000. The default is 300.
Step 10 exit
Example:Router(config)# exit
Exits global configuration mode and returns the router to privileged EXEC mode.
Command or Action Purpose
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interval specifies the amount of time the switch waits to hear BPDUs from the root switch. If a switch does not hear BPDUs from the root switch within the specified interval, it recomputes the spanning-tree topology.
Note Each switch in a spanning tree adopts the interval between hello BPDUs, the forward delay interval, and the maximum idle interval parameters of the root switch, regardless of what its individual configuration might be.
SUMMARY STEPS
1. enable
2. configure terminal
3. bridge bridge-group hello-time seconds
4. bridge bridge-group forward-time seconds
5. bridge bridge-group max-age seconds
6. exit
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 bridge bridge-group hello-time seconds
Example:Router(config)# bridge 10 hello-time 5
Specifies the interval between hello BPDUs.
• Use the bridge-group argument to specify the bridge group number. The range is from 1 to 255.
• Use the seconds argument to enter a number from 1 to 10. The default is 2 seconds.
Step 4 bridge bridge-group forward-time seconds
Example:Router(config)# bridge 10 forward-time 10
Specifies the forward-delay interval.
• Use the bridge-group argument to specify the bridge group number. The range is from 1 to 255.
• Use the seconds argument to enter a number from 10 to 200. The default is 20 seconds.
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Disabling the Spanning Tree on an Interface
Perform this task to disable spanning tree on an interface. When a loop-free path exists between any two switched subnetworks, you can prevent BPDUs generated in one switching subnetwork from impacting devices in the other switching subnetwork, yet still permit switching throughout the network as a whole. For example, when switched LAN subnetworks are separated by a WAN, BPDUs can be prevented from traveling across the WAN link.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
4. bridge bridge-group spanning-disabled
5. exit
DETAILED STEPS
Step 5 bridge-group bridge-group max-age seconds
Example:Router(config)# bridge-group 10 max-age 30
Specifies the interval the switch waits to hear BPDUs from the root switch.
• Use the bridge-group argument to specify the bridge group number. The range is from 1 to 255.
• Use the seconds argument to enter a number from 10 to 200. The default is 30 seconds.
Step 6 exit
Example:Router(config)# exit
Exits global configuration mode and returns the router to privileged EXEC mode.
Command or Action Purpose
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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Configuring Network Security with ACLs at Layer 2This section contains the following tasks:
• Configuring a Numbered Standard ACL, page 303
• Configuring a Numbered Extended ACL, page 305
• Configuring a Named Standard ACL, page 308
• Configuring a Named Extended ACL, page 310
• Applying the ACL to an Interface, page 311
Configuring ACLs on Layer 2 interfaces is the same as configuring ACLs on Cisco routers. The process is briefly described here. For more detailed information on configuring router ACLs, refer to the “Configuring IP Services” chapter in the Cisco IP Configuration Guide. For detailed information about the commands, refer to Cisco IOS IP Command Reference for Cisco IOS Release 12.3 T. For a list of Cisco IOS features not supported on the EtherSwitch network module, see the following section.
Restrictions
The EtherSwitch network module does not support these Cisco IOS router ACL-related features:
• Non-IP protocol ACLs (see Table 21 on page 302).
• Bridge-group ACLs.
• IP accounting.
• ACL support on the outbound direction.
• Inbound and outbound rate limiting (except with QoS ACLs).
• IP packets with a header length of less than five are not to be access-controlled.
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface gigabitethernet 0/1
Selects the Ethernet interface on which the bridge group is assigned and enters interface configuration mode.
The specified interface must be one of the following:
• A routed port: a physical port that you have configured as a Layer 3 port by entering the no switchport interface configuration command.
• An SVI: a VLAN interface that you created by using the interface vlan vlan-id global configuration command.
• These ports must have IP addresses assigned to them.
Step 4 bridge bridge-group spanning-disabled
Example:Router(config-if)# bridge 10 spanning-disabled
Disables spanning tree on the interface.
• Use the bridge-group argument to specify the bridge group number. The range is from 1 to 255.
Step 5 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns to global configuration mode.
• Repeat this command to exit global configuration mode and return to privileged EXEC mode.
Command or Action Purpose
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• Reflexive ACLs.
• Dynamic ACLs.
• ICMP-based filtering.
• IGMP-based filtering.
Creating Standard and Extended IP ACLs
This section describes how to create switch IP ACLs. An ACL is a sequential collection of permit and deny conditions. The switch tests packets against the conditions in an access list one by one. The first match determines whether the switch accepts or rejects the packet. Because the switch stops testing conditions after the first match, the order of the conditions is critical. If no conditions match, the switch denies the packet.
An ACL must first be created by specifying an access list number or name and access conditions. The ACL can then be applied to interfaces or terminal lines.
The software supports these styles of ACLs or IP access lists:
• Standard IP access lists use source addresses for matching operations.
• Extended IP access lists use source and destination addresses for matching operations and optional protocol-type information for finer granularity of control.
ACL Numbers
The number you use to denote your ACL shows the type of access list that you are creating. Table 21 lists the access list number and corresponding type and shows whether or not they are supported by the switch. The EtherSwitch network module supports IP standard and IP extended access lists, numbers 1 to 199 and 1300 to 2699.
Table 21 Access List Numbers
ACL Number Type Supported
1–99 IP standard access list Yes
100–199 IP extended access list Yes
200–299 Protocol type-code access list No
300–399 DECnet access list No
400–499 XNS standard access list No
500–599 XNS extended access list No
600–699 AppleTalk access list No
700–799 48-bit MAC address access list No
800–899 IPX standard access list No
900–999 IPX extended access list No
1000–1099 IPX SAP access list No
1100–1199 Extended 48-bit MAC address access list No
1200–1299 IPX summary address access list No
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Note In addition to numbered standard and extended ACLs, you can also create standard and extended named IP ACLs by using the supported numbers. That is, the name of a standard IP ACL can be 1 to 99; the name of an extended IP ACL can be 100 to 199. The advantage of using named ACLs instead of numbered lists is that you can delete individual entries from a named list.
Note An attempt to apply an unsupported ACL feature to an EtherSwitch network module interface produces an error message.
Including Comments About Entries in ACLs
You can use the remark command to include comments (remarks) about entries in any IP standard or extended ACL. The remarks make the ACL easier for you to understand and scan. Each remark line is limited to 100 characters.
The remark can go before or after a permit or deny statement. You should be consistent about where you put the remark so that it is clear which remark describes which permit or deny statement. For example, it would be confusing to have some remarks before the associated permit or deny statements and some remarks after the associated statements.
For IP numbered standard or extended ACLs, use the access-list access-list number remark remark global configuration command to include a comment about an access list. To remove the remark, use the no form of this command.
For an entry in a named IP ACL, use the remark access-list global configuration command. To remove the remark, use the no form of this command.
Configuring a Numbered Standard ACL
Perform this task to create a numbered standard ACL.
Note When creating an ACL, remember that, by default, the end of the ACL contains an implicit deny statement for all packets that it did not find a match for before reaching the end. With standard access lists, if you omit the ask from an associated IP host address ACL specification, 0.0.0.0 is assumed to be the mask.
SUMMARY STEPS
1. enable
2. configure terminal
3. access-list access-list-number {deny | permit | remark} {source source-wildcard | host source | any}
1300–1999 IP standard access list (expanded range) Yes
2000–2699 IP extended access list (expanded range) Yes
Table 21 Access List Numbers (continued)
ACL Number Type Supported
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4. exit
5. show access-lists [number | name]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 access-list access-list-number {deny | permit | remark} {source source-wildcard | host source | any}
Example:Router(config)# access-list 2 deny host 172.17.198.102
Defines a standard IP ACL by using a source address and wildcard.
• The access-list-number is a decimal number from 1 to 99 or 1300 to 1999.
• Enter the deny or permit keywords to specify whether to deny or permit access if conditions are matched.
• The source is the source address of the network or host from which the packet is being sent, and is a 32-bit number in dotted-decimal format.
• The source-wildcard applies wildcard bits to the source address.
• The keyword host as an abbreviation for source and source-wildcard of source 0.0.0.0.
• The keyword any as an abbreviation for source and source-wildcard of 0.0.0.0 255.255.255.255. You do not need to enter a source-wildcard.
Step 4 exit
Example:Router(config)# exit
Exits global configuration mode and returns the router to privileged EXEC mode.
Step 5 show access-lists [number | name]
Example:Router# show access-lists
Displays access list configuration information.
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Configuring a Numbered Extended ACL
Perform this task to create a numbered extended ACL.
Extended ACLs
Although standard ACLs use only source addresses for matching, you can use an extended ACL source and destination addresses for matching operations and optional protocol type information for finer granularity of control. Some protocols also have specific parameters and keywords that apply to that protocol.
These IP protocols are supported (protocol keywords are in parentheses in bold): Internet Protocol (ip), Transmission Control Protocol (tcp), or User Datagram Protocol (udp).
Supported parameters can be grouped into these categories:
• TCP
• UDP
Table 22 lists the possible filtering parameters for ACEs for each protocol type.
For more details on the specific keywords relative to each protocol, refer to the Cisco IP Command Reference for Cisco IOS Release 12.3 T.
Note The EtherSwitch network module does not support dynamic or reflexive access lists. It also does not support filtering based on the minimize-monetary-cost type of service (TOS) bit.
When creating ACEs in numbered extended access lists, remember that after you create the list, any additions are placed at the end of the list. You cannot reorder the list or selectively add or remove ACEs from a numbered list.
Table 22 Filtering Parameter ACEs Supported by Different IP Protocols
Filtering Parameter TCP UDP
Layer 3 Parameters:
IP ToS byte1
1. No support for type of service (TOS) minimize monetary cost bit.
No No
Differentiated Services Code Point (DSCP) No No
IP source address Yes Yes
IP destination address Yes Yes
Fragments No No
TCP or UDP Yes Yes
Layer 4 Parameters
Source port operator Yes Yes
Source port Yes Yes
Destination port operator Yes Yes
Destination port Yes Yes
TCP flag No No
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Use the no access-list access-list-number global configuration command to delete the entire access list. You cannot delete individual ACEs from numbered access lists.
After an ACL is created, any additions (possibly entered from the terminal) are placed at the end of the list. You can add ACEs to an ACL, but deleting any ACE deletes the entire ACL.
Note When creating an ACL, remember that, by default, the end of the access list contains an implicit deny statement for all packets if it did not find a match before reaching the end.
SUMMARY STEPS
1. enable
2. configure terminal
3. access-list access-list-number {deny | permit | remark} protocol {source source-wildcard | host source | any} [operator port] {destination destination-wildcard | host destination | any} [operator port]
4. exit
5. show access-lists [number | name]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
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Step 3 access-list access-list-number {deny | permit | remark} protocol {source source-wildcard | host source | any} [operator port] {destination destination-wildcard | host destination | any} [operator port]
Example:Router(config)# access-list 102 deny tcp 172.17.69.0 0.0.0.255 172.20.52.0 0.0.0.255 eq telnet
Defines an extended IP access list and the access conditions.
• The access-list-number is a decimal number from 100 to 199 or 2000 to 2699.
• Enter the deny or permit keywords to specify whether to deny or permit access if conditions are matched.
• For protocol, enter the name or number of an IP protocol: ip, tcp, or udp. To match any Internet protocol (including TCP and UDP), use the keyword ip.
• The source is the source address of the network or host from which the packet is being sent, and is a 32-bit number in dotted-decimal format.
• The source-wildcard applies wildcard bits to the source address.
• The keyword host as an abbreviation for source and source-wildcard of source 0.0.0.0.
• The keyword any as an abbreviation for source and source-wildcard of 0.0.0.0 255.255.255.255. You do not need to enter a source-wildcard.
• The operator defines a destination or source port and can be only eq (equal).
• If operator is after source source-wildcard, conditions match when the source port matches the defined port.
• If operator is after destination destination-wildcard, conditions match when the destination port matches the defined port.
• The port is a decimal number or name of a TCP or UDP port. The number can be from 0 to 65535.
• Use TCP port names only for TCP traffic.
• Use UDP port names only for UDP traffic.
Note Only the ip, tcp, and udp protocols are supported on Ethernet switch interfaces.
• The destination is the address of the network or host to which the packet is being sent, and is a 32-bit number in dotted-decimal format.
• The destination-wildcard applies wildcard bits to the destination address.
• The keyword host as an abbreviation for destination and destination-wildcard of destination 0.0.0.0.
• The keyword any as an abbreviation for destination and destination-wildcard of 0.0.0.0 255.255.255.255.
Command or Action Purpose
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What to Do Next
After creating an ACL, you must apply it to an interface, as described in the “Applying the ACL to an Interface” section on page 311.
Configuring a Named Standard ACL
Perform this task to create a named standard ACL.
Named Standard ACL Creation
You can identify IP ACLs with an alphanumeric string (a name) rather than a number. You can use named ACLs to configure more IP access lists on a switch than if you use numbered access lists. If you identify your access list with a name rather than a number, the mode and command syntax are slightly different. However, not all commands that use IP access lists accept a named ACL.
Note The name you give to a standard ACL or extended ACL can also be a number in the supported range of access list numbers. That is, the name of a standard IP ACL can be 1 to 99; the name of an extended IP ACL can be 100 to 199. The advantage of using named ACLs instead of numbered lists is that you can delete individual entries from a named list.
Consider these guidelines and limitations before configuring named ACLs:
• A standard ACL and an extended ACL cannot have the same name.
• Numbered ACLs are also available, as described in the “Creating Standard and Extended IP ACLs” section on page 302.
Note When creating an ACL, remember that, by default, the end of the ACL contains an implicit deny statement for all packets that it did not find a match for before reaching the end. With standard access lists, if you omit the ask from an associated IP host address ACL specification, 0.0.0.0 is assumed to be the mask.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip access-list standard {access-list-number | name}
Step 4 exit
Example:Router(config)# exit
Exits global configuration mode and returns the router to privileged EXEC mode.
Step 5 show access-lists [number | name]
Example:Router# show access-lists
Displays access list configuration information.
Command or Action Purpose
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4. deny {source source-wildcard | host source | any}orpermit {source source-wildcard | host source | any}
5. exit
6. show access-lists [number | name]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip access-list standard {access-list-number | name}
Example:Router(config)# ip access-list standard sales
Defines a standard IP access list using a name and enters access-list configuration mode.
• The name argument can be a decimal number from 1 to 99.
Step 4 deny {source source-wildcard | host source | any}
or
permit {source source-wildcard | host source | any}
Example:Router(config-acl# deny 10.2.1.3 any
Example:Router(config-acl)# permit 10.2.1.4 any
Specifies one or more conditions denied or permitted to determine if the packet is forwarded or dropped.
• host source represents a source and source wildcard of source 0.0.0.0.
• any represents a source and source wildcard of 0.0.0.0 255.255.255.255.
Step 5 exit
Example:Router(config)# exit
Exits access-list configuration mode and returns the router to global configuration mode.
• Repeat this command to exit global configuration mode and return to privileged EXEC mode.
Step 6 show access-lists [number | name]
Example:Router# show access-lists sales
Displays access list configuration information.
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Configuring a Named Extended ACL
You can identify IP ACLs with an alphanumeric string (a name) rather than a number. You can use named ACLs to configure more IP access lists on a switch than if you use numbered access lists. If you identify your access list with a name rather than a number, the mode and command syntax are slightly different. However, not all commands that use IP access lists accept a named ACL.
Note The name you give to a standard ACL or extended ACL can also be a number in the supported range of access list numbers. That is, the name of a standard IP ACL can be 1 to 99; the name of an extended IP ACL can be 100 to 199. The advantage of using named ACLs instead of numbered lists is that you can delete individual entries from a named list.
Consider these guidelines and limitations before configuring named ACLs:
• A standard ACL and an extended ACL cannot have the same name.
• Numbered ACLs are also available, as described in the “Creating Standard and Extended IP ACLs” section on page 302.
Note When creating an ACL, remember that, by default, the end of the ACL contains an implicit deny statement for all packets that it did not find a match for before reaching the end. With standard access lists, if you omit the ask from an associated IP host address ACL specification, 0.0.0.0 is assumed to be the mask.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip access-list extended {access-list-number | name}
4. deny protocol {source source-wildcard | host source | any} [operator port] {destination destination-wildcard | host destination | any} [operator port]orpermit {source source-wildcard | host source | any} [operator port] {destination destination-wildcard | host destination | any} [operator port]
5. exit
6. show access-lists [number | name]
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DETAILED STEPS
Applying the ACL to an Interface
Perform this task to control access to a Layer 2 or Layer 3 interface. After you create an ACL, you can apply it to one or more interfaces. ACLs can be applied on inbound interfaces. This section describes how to accomplish this task for network interfaces. Note these guidelines:
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 ip access-list extended {access-list-number | name}
Example:Router(config)# ip access-list extended marketing
Defines an extended IP access list using a name and enters access-list configuration mode.
• The name argument can be a decimal number from 100 to 199.
Step 4 deny {source source-wildcard | host source | any} protocol {source source-wildcard | host source | any} [operator port] {destination destination-wildcard | host destination | any} [operator port]
or
permit {source source-wildcard | host source | any} protocol {source source-wildcard | host source | any} [operator port] {destination destination-wildcard | host destination | any} [operator port]
Example:Router(config-acl# deny tcp any any
or
Router(config-acl)# permit tcp 10.2.1.4 0.0.0.255 eq telnet
Specifies one or more conditions denied or permitted to determine if the packet is forwarded or dropped.
See the “Configuring a Numbered Extended ACL” section on page 305 for definitions of protocols and other keywords.
• host source represents a source and source wildcard of source 0.0.0.0, and host destination represents a destination and destination wildcard of destination 0.0.0.0.
• any represents a source and source wildcard or destination and destination wildcard of 0.0.0.0 255.255.255.255.
Step 5 exit
Example:Router(config-acl)# exit
Exits access-list configuration mode and returns the router to global configuration mode.
• Repeat this command to exit global configuration mode and return to privileged EXEC mode.
Step 6 show access-lists [number | name]
Example:Router# show access-lists marketing
Displays access list configuration information.
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• When controlling access to a line, you must use a number. Numbered ACLs can be applied to lines.
• When controlling access to an interface, you can use a name or number.
Note The ip access-group interface configuration command is only valid when applied to a Layer 2 interface or a Layer 3 interface. If applied to a Layer 3 interface, the interface must have been configured with an IP address. ACLs cannot be applied to interface port-channels.
For inbound ACLs, after receiving a packet, the switch checks the packet against the ACL. If the ACL permits the packet, the switch continues to process the packet. If the ACL rejects the packet, the switch discards the packet.
When you apply an undefined ACL to an interface, the switch acts as if the ACL has not been applied to the interface and permits all packets. Remember this behavior if you use undefined ACLs for network security.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
4. ip access-group {access-list-number | name} in
5. exit
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface gigabitethernet 0/3
Specifies the Ethernet interface to which the ACL will be applied and enters interface configuration mode.
• The interface must be a Layer 2 interface or a routed port.
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Configuring Quality of Service (QoS) on the EtherSwitch network moduleThis section consists of the following tasks that must be performed to configure QoS on your EtherSwitch network module:
• Configuring Classification Using Port Trust States, page 315
• Configuring a QoS Policy, page 317
Prerequisites
Before configuring QoS, you must have a thorough understanding of the following items:
• The types of applications used and the traffic patterns on your network.
• Traffic characteristics and needs of your network. Is the traffic bursty? Do you need to reserve bandwidth for voice and video streams?
• Bandwidth requirements and speed of the network.
• Location of congestion points in the network.
Restrictions
• If you have EtherChannel ports configured on your switch, you must configure QoS classification, policing, mapping, and queueing on the individual physical ports that comprise the EtherChannel. You must decide whether the QoS configuration should match on all ports in the EtherChannel.
• It is not possible to match IP fragments against configured IP extended ACLs to enforce QoS. IP fragments are transmitted as best-effort. IP fragments are denoted by fields in the IP header.
• Control traffic (such as spanning-tree Bridge Protocol Data Units (BPDUs) and routing update packets) received by the switch are subject to all ingress QoS processing.
• Only one ACL per class map and only one match command per class map are supported. The ACL can have multiple access control entries, which are commands that match fields against the contents of the packet.
• Policy maps with ACL classification in the egress direction are not supported and cannot be attached to an interface by using the service-policy input policy-map-name interface configuration command.
• In a policy map, the class named class-default is not supported. The switch does not filter traffic based on the policy map defined by the class class-default policy-map configuration command.
Step 4 ip access-group {access-list-number | name} in
Example:Router(config)# ip access-group sales in
Controls access to the specified interface.
Step 5 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this step one more time to exit global configuration mode.
Command or Action Purpose
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For more information on guidelines for configuring ACLs, see the “Classification Based on QoS ACLs” section on page 238.
QoS on Switching Devices
Default Settings
• The default port CoS value is 0.
• The default port trust state is untrusted.
• No policy maps are configured.
• No policers are configured.
• The default CoS-to-DSCP map is shown in Table 23 on page 322.
• The default DSCP-to-CoS map is shown in Table 24 on page 323.
Trust State on Ports and SVIs Within the QoS Domain
Packets entering a QoS domain are classified at the edge of the QoS domain. When the packets are classified at the edge, the switch port within the QoS domain can be configured to one of the trusted states because there is no need to classify the packets at every switch within the QoS domain. Figure 39 shows a sample network topology.
Figure 39 Port Trusted States within the QoS Domain
1556
91
Cisco router with Ethernetswitch network module
Trunk
Trusted interface
Classificationof trafficperformed here
Catalyst 2950wiring closet
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Configuring Classification Using Port Trust States
Perform this task to configure the port to trust the classification of the traffic that it receives, and then define the default CoS value of a port or to assign the default Cos to all incoming packets on the port.
Note The mls qos cos command replaced the switchport priority command in Cisco IOS Release 12.1(6)EA2.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface {ethernet | fastethernet | gigabitethernet} slot/port
4. mls qos trust {cos | dscp}
5. mls qos cos {default-cos | override}
6. exit
7. show mls qos interface [interface-type slot/port] [policers]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface fastethernet 0/1
Selects the Ethernet interface to be trusted and enters interface configuration mode.
• Valid interfaces include physical interfaces and SVIs.
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Step 4 mls qos trust {cos | dscp}
Example:Router(config-if)# mls qos trust cos
Configures the port trust state.
• By default, the port is not trusted.
• Use the cos keyword setting if your network is composed of Ethernet LANs, Catalyst 2950 switches, and has no more than two types of traffic.
• Use the cos keyword if you want ingress packets to be classified with the packet CoS values. For tagged IP packets, the DSCP value of the packet is modified based on the CoS-to-DSCP map. The egress queue assigned to the packet is based on the packet CoS value.
• Use the dscp keyword if your network is not composed of only Ethernet LANs and if you are familiar with sophisticated QoS features and implementations.
• Use the dscp keyword if you want ingress packets to be classified with packet DSCP values. For non-IP packets, the packet CoS value is used for tagged packets; the default port CoS is used for untagged packets. Internally, the switch modifies the CoS value by using the DSCP-to-CoS map.
• Use the dscp keyword if you are using an SVI that is a VLAN interface that you created by using the interface vlan vlan-id global configuration command. The DCSP-to-CoS map will be applied to packets arriving from a router to the EtherSwitch network module through an SVI.
Step 5 mls qos cos {default-cos | override}
Example:Router(config-if)# mls qos cos 5
Configures the default CoS value for the port.
• Use the default-cos argument to specify a default CoS value to be assigned to a port. If the port is CoS trusted and packets are untagged, the default CoS value becomes the CoS value for the packet. The CoS range is 0 to 7. The default is 0.
• Use the override keyword to override the previously configured trust state of the incoming packets and to apply the default port CoS value to all incoming packets. By default, CoS override is disabled.
• Use the override keyword when all incoming packets on certain ports deserve higher priority than packets entering from other ports. Even if a port was previously set to trust DSCP, this command overrides the previously configured trust state, and all the incoming CoS values are assigned the default CoS value configured with this command. If an incoming packet is tagged, the CoS value of the packet is modified with the default CoS of the port at the ingress port.
Command or Action Purpose
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Examples
The following is sample output from the show mls qos interface fastethernet0/1 command:
Router# show mls qos interface fastethernet 0/1
FastEthernet0/1trust state: trust cosCOS override: disdefault COS: 0
Configuring a QoS PolicyThis section contains the following tasks:
• Classifying Traffic by Using ACLs, page 317
• Classifying Traffic Using Class Maps, page 317
• Classifying, Policing, and Marking Traffic Using Policy Maps, page 319
Configuring a QoS policy typically requires classifying traffic into classes, configuring policies applied to those traffic classes, and attaching policies to interfaces.
For background information, see the “Classification” section on page 238 and the “Policing and Marking” section on page 239.
Classifying Traffic by Using ACLs
You can classify IP traffic by using IP standard or IP extended ACLs. To create an IP standard ACL for IP traffic, refer to the “Configuring a Numbered Standard ACL” section on page 303 and to create an IP extended ACL for IP traffic refer to the “Configuring a Numbered Extended ACL” section on page 305.
Classifying Traffic Using Class Maps
Perform this task to create a class map and to define the match criteria for classifying traffic. You use the class-map global configuration command to isolate a specific traffic flow (or class) from all other traffic and to name it. The class map defines the criteria to use to match against a specific traffic flow to further classify it. Match statements can include criteria such as an ACL. The match criterion is defined with one match statement entered within the class-map configuration mode.
Step 6 exit
Example:Router(config-if)# exit
Exits interface configuration mode and returns the router to global configuration mode.
• Repeat this step one more time to exit global configuration mode.
Step 7 show mls qos interface [interface-type slot/port] [policers]
Example:Router# show mls qos interface fastethernet 0/1
(Optional) Displays information about Fast Ethernet interfaces.
Command or Action Purpose
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Note You can also create class maps during policy map creation by using the class policy-map configuration command. For more information, see the “Classifying, Policing, and Marking Traffic Using Policy Maps” section on page 319.
SUMMARY STEPS
1. enable
2. configure terminal
3. access-list access-list-number {deny | permit | remark} {source source-wildcard | host source | any}oraccess-list access-list-number {deny | permit | remark} protocol {source source-wildcard | host source | any} [operator-port] {destination destination-wildcard | host destination | any} [operator-port]
4. class-map class-map-name
5. match access-group acl-index-or-name
6. exit
7. show class-map [class-map-name]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 access-list access-list-number {deny | permit | remark} {source source-wildcard | host source | any}
or
access-list access-list-number {deny | permit | remark} protocol {source source-wildcard | host source | any} [operator port] {destination destination-wildcard | host destination | any} [operator port]
Example:Router(config)# access-list 103 permit any any tcp eq 80
Creates an IP standard or extended ACL for IP traffic.
• Repeat this command as many times as necessary.
• For more information, see the “Configuring a Numbered Standard ACL” section on page 303 and the “Configuring a Numbered Extended ACL” section on page 305.
• Deny statements are not supported for QoS ACLS. See the “Classification Based on QoS ACLs” section on page 238 for more details.
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Classifying, Policing, and Marking Traffic Using Policy Maps
Perform this task to create a policy map. A policy map specifies which traffic class to act on. Actions can include trusting the CoS or DSCP values in the traffic class; setting a specific DSCP value in the traffic class; and specifying the traffic bandwidth limitations for each matched traffic class (policer) and the action to take when the traffic is out of profile (marking).
A separate policy-map class can exist for each type of traffic received through an interface. You can attach only one policy map per interface in the input direction.
SUMMARY STEPS
1. enable
2. configure terminal
3. access-list access-list-number {deny | permit | remark} {source source-wildcard | host source | any}oraccess-list access-list-number {deny | permit | remark} protocol {source source-wildcard | host source | any} [operator-port] {destination destination-wildcard | host destination | any} [operator-port]
4. policy-map policy-map-name
5. class class-map-name [access-group acl-index-or-name]
6. police {bps | cir bps} [burst-byte | bc burst-byte] conform-action transmit [exceed-action {drop | dscp dscp-value}]
7. exit
Step 4 class-map class-map-name
Example:Router(config)# class-map class1
Creates a class map, and enters class-map configuration mode.
• By default, no class maps are defined.
• Use the class-map-name argument to specify the name of the class map.
Step 5 match access-group acl-index-or-name
Example:Router(config-cmap)# match access-group 103
Defines the match criteria to classify traffic.
• By default, no match criteria is supported.
• Only one match criteria per class map is supported, and only one ACL per class map is supported.
• Use the acl-index-or-name argument to specify the number or name of the ACL created in Step 3.
Step 6 exit
Example:Router(config-cmap)# exit
Exits class map configuration mode and returns the router to global configuration mode.
• Repeat this step one more time to exit global configuration mode.
Step 7 show class-map [class-map-name]
Example:Router# show class-map class1
(Optional) Displays class maps and their matching criteria.
Command or Action Purpose
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8. interface {ethernet | fastethernet | gigabitethernet} slot/port
9. service-policy input policy-map-name
10. exit
11. show policy-map policy-map-name class class-name
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 access-list access-list-number {deny | permit | remark} {source source-wildcard | host source | any}
or
access-list access-list-number {deny | permit | remark} protocol {source source-wildcard | host source | any} [operator port] {destination destination-wildcard | host destination | any} [operator port]
Example:Router(config)# access-list 1 permit 10.1.0.0 0.0.255.255
Creates an IP standard or extended ACL for IP traffic.
• Repeat this command as many times as necessary.
• For more information, see the “Configuring a Numbered Standard ACL” section on page 303 and the “Configuring a Numbered Extended ACL” section on page 305.
Note Deny statements are not supported for QoS ACLS. See the “Classification Based on QoS ACLs” section on page 238 for more details.
Step 4 policy-map policy-map-name
Example:Router(config)# policy-map flow1t
Creates a policy map by entering the policy map name, and enters policy-map configuration mode.
• By default, no policy maps are defined.
• The default behavior of a policy map is to set the DSCP to 0 if the packet is an IP packet and to set the CoS to 0 if the packet is tagged. No policing is performed.
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Step 5 class {class-map-name | class-default} [access-group acl-index-or-name]
Example:Router(config-pmap)# class ipclass1
Defines a traffic classification, and enters policy-map class configuration mode.
• By default, no policy map class maps are defined.
• If a traffic class has already been defined by using the class-map global configuration command, specify its name for class-map-name in this command.
• For access-group acl-index-or-name, specify the number or name of the ACL created in Step 3.
• In a policy map for the EtherSwitch network module, the class named class-default is not supported. The switch does not filter traffic based on the policy map defined by the class class-default policy-map configuration command.
Step 6 police {bps | cir bps} [burst-byte | bc burst-byte] conform-action transmit [exceed-action {drop | dscp dscp-value}]
Example:Router(config-pmap)# police 5000000 8192 conform-action transmit exceed-action dscp 10
Defines a policer for the classified traffic.
• You can configure up to 60 policers on ingress Gigabit-capable Ethernet ports and up to 6 policers on ingress 10/100 Ethernet ports.
• For bps, specify average traffic rate or committed information rate in bits per second (bps). The range is 1 Mbps to 100 Mbps for 10/100 Ethernet ports and 8 Mbps to 1000 Mbps for the Gigabit-capable Ethernet ports.
• For burst-byte, specify the normal burst size or burst count in bytes.
• (Optional) Specify the action to take when the rates are exceeded. Use the exceed-action drop keywords to drop the packet. Use the exceed-action dscp dscp-value keywords to mark down the DSCP value and transmit the packet.
Step 7 exit
Example:Router(config-pmap)# exit
Exits policy map configuration mode and returns the router to global configuration mode.
Step 8 interface {ethernet | fastethernet | gigabitethernet} slot/port
Example:Router(config)# interface fastethernet 5/6
Enters interface configuration mode, and specifies the interface to attach to the policy map.
• Valid interfaces include physical interfaces.
Step 9 service-policy input policy-map-name
Example:Router(config-if)# service-policy input flow1t
Applies a policy map to the input of a particular interface.
• Only one policy map per interface per direction is supported.
• Use input policy-map-name to apply the specified policy map to the input of an interface.
Command or Action Purpose
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Configuring the CoS-to-DSCP Map
Perform this task to modify the CoS-to-DSCP map. You use the CoS-to-DSCP map to map CoS values in incoming packets to a DSCP value that QoS uses internally to represent the priority of the traffic.
Table 23 shows the default CoS-to-DSCP map.
If these values are not appropriate for your network, you need to modify them. These CoS-to-DSCP mapping numbers follow the numbers used in deploying Cisco AVVID and may be different from the mapping numbers used by the EtherSwitch network module, Cisco Catalyst 2950, Cisco Catalyst 3550, and other switches.
SUMMARY STEPS
1. enable
2. configure terminal
3. mls qos map cos-dscp dscp1...dscp8
4. exit
5. show mls qos maps cos-dscp
Step 10 exit
Example:Router(config-class-map)# exit
Exits class map configuration mode and returns the router to global configuration mode.
• Repeat this step one more time to exit global configuration mode.
Step 11 show policy-map policy-map-name class class-map-name
Example:Router# show policy-map flow1t class class1
(Optional) Displays the configuration for the specified class of the specified policy map.
Command or Action Purpose
Table 23 Default CoS-to-DSCP Map
CoS value 0 1 2 3 4 5 6 7
DSCP value 0 8 16 26 32 46 48 56
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DETAILED STEPS
Configuring the DSCP-to-CoS Map
Perform this task to modify the DSCP-to-CoS map. You use the DSCP-to-CoS map to map DSCP values in incoming packets to a CoS value, which is used to select one of the four egress queues. The EtherSwitch network modules support these DSCP values: 0, 8, 10, 16, 18, 24, 26, 32, 34, 40, 46, 48, and 56.
Table 24 shows the default DSCP-to-CoS map.
If these values are not appropriate for your network, you need to modify them. These DSCP-to-CoS mapping numbers follow the numbers used in deploying Cisco AVVID and may be different from the mapping numbers used by the EtherSwitch network module, Cisco Catalyst 2950, Cisco Catalyst 3550, and other switches.
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 mls qos map cos-dscp dscp1...dscp8
Example:Router(config)# mls qos map cos-dscp 8 8 8 8 24 32 56 56
Modifies the CoS-to-DSCP map.
• For dscp1...dscp8, enter eight DSCP values that correspond to CoS values 0 to 7. Separate each DSCP value with a space.
• The supported DSCP values are 0, 8, 10, 16, 18, 24, 26, 32, 34, 40, 46, 48, and 56.
Step 4 exit
Example:Router(config)# exit
Exits global configuration mode and returns the router to privileged EXEC mode.
Step 5 show mls qos maps cos-dscp
Example:Router# show mls qos maps cos-dscp
(Optional) Displays the CoS-to-DSCP map.
Table 24 Default DSCP-to-CoS Map
DSCP values 0 8, 10 16, 18 24, 26 32, 34 40, 46 48 56
CoS values 0 1 2 3 4 5 6 7
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SUMMARY STEPS
1. enable
2. configure terminal
3. mls qos map dscp-cos dscp-list to cos
4. exit
5. show mls qos maps dscp-to-cos
DETAILED STEPS
Configuration Examples for the EtherSwitch Network ModuleThis section contains the following configuration examples:
• Configuring VLANs: Example, page 325
• Configuring VTP: Example, page 325
• Configuring Spanning Tree: Examples, page 326
• Configuring Layer 2 Interfaces: Examples, page 327
Command or Action Purpose
Step 1 enable
Example:Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Step 2 configure terminal
Example:Router# configure terminal
Enters global configuration mode.
Step 3 mls qos map dscp-cos dscp-list to cos
Example:Router(config)# mls qos map dscp-cos 26 48 to 7
Modifies the DSCP-to-CoS map.
• For dscp-list, enter up to 13 DSCP values separated by spaces. Then enter the to keyword.
• For cos, enter the CoS value to which the DSCP values correspond.
• The supported DSCP values are 0, 8, 10, 16, 18, 24, 26, 32, 34, 40, 46, 48, and 56. The CoS range is 0 to 7.
Step 4 exit
Example:Router(config)# exit
Exits global configuration mode and returns the router to privileged EXEC mode.
Step 5 show mls qos maps dscp-to-cos
Example:Router# show mls qos maps dscp-to-cos
(Optional) Displays the DSCP-to-CoS map.
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• Configuring Voice and Data VLANs: Examples, page 328
• Configuring 802.1x Authentication: Examples, page 330
• Configuring Storm-Control: Example, page 331
• Configuring Layer 2 EtherChannels: Example, page 332
• Configuring Flow Control on Gigabit Ethernet Ports: Example, page 332
• Intrachassis Stacking: Example, page 335
• Configuring Switched Port Analyzer (SPAN): Example, page 336
• Configuring Layer 3 Interfaces: Example, page 336
• IGMP Snooping: Example, page 337
• Configuring Fallback Bridging: Examples, page 339
• Configuring Network Security with ACLs at Layer 2: Examples, page 341
• Configuring QoS on the EtherSwitch network module: Examples, page 346
Configuring VLANs: ExampleThe following example shows how to configure a VLAN:
Router# vlan databaseRouter(vlan)# vlan 2 media ethernet name vlan1502VLAN 2 added:Name: VLAN1502Router(vlan)# exit APPLY completed.Exiting....
Configuring VTP: ExampleThe following example shows how to configure a VTP server, configure a VTP client, configure VTP version 2, and disable VTP mode on the router:
Router# vlan databaseRouter(vlan)# vtp serverSetting device to VTP SERVER mode.Router(vlan)# vtp domain Lab_NetworkSetting VTP domain name to Lab_NetworkRouter(vlan)# vtp password WATERSetting device VLAN database password to WATER.Router(vlan)# vtp clientSetting device to VTP CLIENT mode.Router(vlan)# vtp v2-modeV2 mode enabled.Router(vlan)# vtp transparentSetting device to VTP TRANSPARENT mode.Router(vlan)# exitAPPLY completed.Exiting....
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Configuring Spanning Tree: ExamplesThe following example shows spanning tree being enabled on VLAN 200 and the bridge priority set to 33792. The hello time for VLAN 200 is set at 7 seconds, the forward delay time set at 21 seconds, and the maximum aging time at 36 seconds. BackboneFast is enable, the VLAN port priority of an interface is configured to be 64 and the spanning tree port cost of the Fast Ethernet interface 5/8 is set at 18.
Router# configure terminal Router(config)# spanning-tree vlan 200 Router(config)# spanning-tree vlan 200 priority 33792 Router(config)# spanning-tree vlan 200 hello-time 7 Router(config)# spanning-tree vlan 200 forward-time 21 Router(config)# spanning-tree vlan 200 max-age 36 Router(config)# spanning-tree backbonefast Router(config-if)# exit Router(config)# interface fastethernet 5/8 Router(config-if)# spanning-tree vlan 200 port-priority 64 Router(config-if)# spanning-tree cost 18 Router(config-if)# exit Router(config)# exit
The following example shows how to verify the configuration of VLAN 200 on the interface when it is configured as a trunk port:
Router# show spanning-tree vlan 200
Port 264 (FastEthernet5/8) of VLAN200 is forwardingPort path cost 19, Port priority 64, Port Identifier 129.8. Designated root has priority 32768, address 0010.0d40.34c7 Designated bridge has priority 32768, address 0010.0d40.34c7 Designated port id is 128.1, designated path cost 0 Timers: message age 2, forward delay 0, hold 0 Number of transitions to forwarding state: 1 BPDU: sent 0, received 13513
The following example shows how to verify the configuration of the interface when it is configured as an access port:
Router# show spanning-tree interface fastethernet 5/8
Port 264 (FastEthernet5/8) of VLAN200 is forwarding Port path cost 18, Port priority 100, Port Identifier 129.8. Designated root has priority 32768, address 0010.0d40.34c7 Designated bridge has priority 32768, address 0010.0d40.34c7 Designated port id is 128.1, designated path cost 0 Timers: message age 2, forward delay 0, hold 0 Number of transitions to forwarding state: 1 BPDU: sent 0, received 13513
The following example shows spanning tree being enabled on VLAN 150:
Router# configure terminal Router(config)# spanning-tree vlan 150 Router(config)# end Router#
Note Because spanning tree is enabled by default, issuing a show running-config command to view the resulting configuration will not display the command you entered to enable spanning tree.
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The following example shows spanning tree being disabled on VLAN 200:
Router# configure terminal Router(config)# no spanning-tree vlan 200 Router(config)# end
The following example shows the switch device being configured as the root bridge for VLAN 10, with a network diameter of 4:
Router# configure terminal Router(config)# spanning-tree vlan 10 root primary diameter 4 Router(config)# exit
Configuring Layer 2 Interfaces: ExamplesThis section contains the following examples:
• Single Range Configuration: Example, page 327
• Multiple Range Configuration: Example, page 327
• Range Macro Definition: Example, page 328
• Optional Interface Features: Example, page 328
• Configuring an Ethernet Interface as a Layer 2 Trunk: Example, page 328
Single Range Configuration: Example
The following example shows all Fast Ethernet interfaces 5/1 to 5/5 being reenabled:
Router(config)# interface range fastethernet 5/1 - 5 Router(config-if)# no shutdown Router(config-if)#*Oct 6 08:24:35: %LINK-3-UPDOWN: Interface FastEthernet5/1, changed state to up*Oct 6 08:24:35: %LINK-3-UPDOWN: Interface FastEthernet5/2, changed state to up*Oct 6 08:24:35: %LINK-3-UPDOWN: Interface FastEthernet5/3, changed state to up*Oct 6 08:24:35: %LINK-3-UPDOWN: Interface FastEthernet5/4, changed state to up*Oct 6 08:24:35: %LINK-3-UPDOWN: Interface FastEthernet5/5, changed state to up*Oct 6 08:24:36: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet5/5, changed state to up*Oct 6 08:24:36: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet5/3, changed state to up*Oct 6 08:24:36: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet5/4, changed state to upRouter(config-if)#
Multiple Range Configuration: Example
The following example shows how to use a comma to add different interface type strings to the range to reenable all Fast Ethernet interfaces in the range 5/1 to 5/5 and both Gigabit Ethernet interfaces 1/1 and 1/2:
Router(config-if)# interface range fastethernet 5/1 - 5, gigabitethernet 1/1 - 2 Router(config-if)# no shutdown Router(config-if)#*Oct 6 08:29:28: %LINK-3-UPDOWN: Interface FastEthernet5/1, changed state to up*Oct 6 08:29:28: %LINK-3-UPDOWN: Interface FastEthernet5/2, changed state to up*Oct 6 08:29:28: %LINK-3-UPDOWN: Interface FastEthernet5/3, changed state to up*Oct 6 08:29:28: %LINK-3-UPDOWN: Interface FastEthernet5/4, changed state to up*Oct 6 08:29:28: %LINK-3-UPDOWN: Interface FastEthernet5/5, changed state to up
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*Oct 6 08:29:28: %LINK-3-UPDOWN: Interface GigabitEthernet1/1, changed state to up*Oct 6 08:29:28: %LINK-3-UPDOWN: Interface GigabitEthernet1/2, changed state to up*Oct 6 08:29:29: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet5/5, changed state to up*Oct 6 08:29:29: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet5/3, changed state to up*Oct 6 08:29:29: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet5/4, changed state to upRouter(config-if)#
Range Macro Definition: Example
The following example shows an interface-range macro named enet_list being defined to select Fast Ethernet interfaces 5/1 through 5/4:
Router(config)# define interface-range enet_list fastethernet 5/1 - 4
Router(config)#
The following example shows how to change to the interface-range configuration mode using the interface-range macro enet_list:
Router(config)# interface range macro enet_list
Router(config-if)#
Optional Interface Features: Example
The following example shows the interface speed being set to 100 Mbps on the Fast Ethernet interface 5/4, the interface duplex mode set to full, and a description being added for the interface:
Router(config)# interface fastethernet 5/4Router(config-if)# speed 100Router(config-if)# duplex fullRouter(config-if)# description Channel-group to "Marketing"
Configuring an Ethernet Interface as a Layer 2 Trunk: Example
The following example shows how to configure the Fast Ethernet interface 5/8 as an 802.1Q trunk. This example assumes that the neighbor interface is configured to support 802.1Q trunking:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z.Router(config)# interface fastethernet 5/8 Router(config-if)# shutdownRouter(config-if)# switchport trunk encapsulation dot1q Router(config-if)# switchport mode trunk Router(config-if)# no shutdown Router(config-if)# end Router# exit
Configuring Voice and Data VLANs: ExamplesThis section contains the following examples:
• Separate Voice and Data VLANs: Example, page 329
• Inter-VLAN Routing: Example, page 329
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• Single Subnet Configuration: Example, page 330
• Ethernet Ports on IP Phones with Multiple Ports: Example, page 330
Separate Voice and Data VLANs: Example
The following example shows separate VLANs being configured for voice and data on the EtherSwitch network module:
interface fastethernet5/1 description DOT1Q port to IP Phone switchport native vlan 50 switchport mode trunk switchport voice vlan 150
interface vlan 150 description voice vlan ip address 10.150.1.1 255.255.255.0 ip helper-address 172.20.73.14 (See Note below)
interface vlan 50 description data vlan ip address 10.50.1.1 255.255.255.0
This configuration instructs the IP phone to generate a packet with an 802.1Q VLAN ID of 150 with an 802.1p value of 5 (default for voice bearer traffic).
Note In a centralized CallManager deployment model, the DHCP server might be located across the WAN link. If so, an ip helper-address command pointing to the DHCP server should be included on the voice VLAN interface for the IP phone. This is done to obtain its IP address as well as the address of the TFTP server required for its configuration.
Cisco IOS supports a DHCP server function. If this function is used, the EtherSwitch network module serves as a local DHCP server and a helper address would not be required.
Inter-VLAN Routing: Example
Configuring inter-VLAN routing is identical to the configuration on an EtherSwitch network module with an MSFC. Configuring an interface for WAN routing is consistent with other Cisco IOS platforms.
The following example provides a sample configuration:
interface vlan 160description voice vlanip address 10.6.1.1 255.255.255.0
interface vlan 60description data vlanip address 10.60.1.1 255.255.255.0
interface serial1/0ip address 172.16.1.2 255.255.255.0
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Note Standard IGP routing protocols such as RIP, IGRP, EIGRP, and OSPF are supported on the EtherSwitch network module. Multicast routing is also supported for PIM dense mode, sparse mode, and sparse-dense mode.
Single Subnet Configuration: Example
The EtherSwitch network module supports the use of an 802.1p-only option when configuring the voice VLAN. Using this option allows the IP phone to tag VoIP packets with a CoS of 5 on the native VLAN, while all PC data traffic is sent untagged.
The following example shows a single subnet configuration for the EtherSwitch network module switch:
interface fastethernet 5/2description Port to IP Phone in single subnetswitchport access vlan 40switchport voice vlan dot1pspanning-tree portfast
The EtherSwitch network module instructs the IP phone to generate an 802.1Q frame with a null VLAN ID value but with an 802.1p value (default is COS of 5 for bearer traffic). The voice and data VLANs are both 40 in this example.
Ethernet Ports on IP Phones with Multiple Ports: Example
The following example illustrates the configuration on the IP phone:
interface fastethernet 2/2switchport voice vlan 5switchport mode trunk
The following example illustrates the configuration on the PC:
interface fastethernet 2/3switchport access vlan 10
Note Using a separate VLAN, and possibly a separate IP address space, may not be an option for some small branch offices due to the IP routing configuration. If the IP routing can handle an additional VLAN at the remote branch, you can use Cisco Network Registrar and secondary addressing.
Configuring 802.1x Authentication: ExamplesThis section contains the following examples:
• Enabling 802.1x Authentication: Example, page 331
• Configuring the Switch-to-RADIUS-Server Communication: Example, page 331
• Configuring 802.1x Parameters: Example, page 331
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Enabling 802.1x Authentication: Example
The following example shows how to enable AAA and 802.1x on Fast Ethernet port 0/1:
Router# configure terminalRouter(config)# aaa new-modelRouter(config)# aaa authentication dot1x default group radiusRouter(config)# interface fastethernet0/1Router(config-if)# dot1x port-control autoRouter(config-if)# end
Configuring the Switch-to-RADIUS-Server Communication: Example
The following example shows how to specify the server with IP address 172.20.39.46 as the RADIUS server, to use port 1612 as the authorization port, and to set the encryption key to rad123, matching the key on the RADIUS server:
Router(config)# radius-server host 172.40.39.46 auth-port 1612 key rad123
Configuring 802.1x Parameters: Example
The following example shows how to enable periodic reauthentication, set the number of seconds between reauthentication attempts to 4000, and set the quiet time to 30 seconds on the EtherSwitch network module. The number of seconds to wait for an EAP-request/identity frame before transmitting is set to 60 seconds and the number of times the switch device will send the EAP-request/identity frames before restarting the authentication process is set to 5. 802.1x is enabled on Fast Ethernet interface 0/1 and multiple hosts are permitted.
Router(config)# dot1x re-authenticationRouter(config)# dot1x timeout re-authperiod 4000Router(config)# dot1x timeout quiet-period 30Router(config)# dot1x timeout tx-period 60Router(config)# dot1x max-req 5Router(config)# interface fastethernet0/1Router(config-if)# dot1x port-control autoRouter(config-if)# dot1x multiple-hosts
Configuring Storm-Control: ExampleThe following example shows global multicast suppression being enabled at 70 percent on Gigabit Ethernet interface 1 and the configuration being verified:
Router# configure terminalRouter(config)# interface gigabitethernet0/2Router(config-if)# storm-control multicast level 70Router(config-if)# endRouter# show storm-control
Name: Gi0/2Switchport: EnabledAdministrative Mode: dynamic desirableOperational Mode: downAdministrative Trunking Encapsulation: dot1qNegotiation of Trunking: OnAccess Mode VLAN: 1 (default)Trunking Native Mode VLAN: 1 (default)Trunking VLANs Enabled: ALLPruning VLANs Enabled: 2-1001
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Port Protected: OffUnknown Unicast Traffic: AllowedUnknown Multicast Traffic: Not Allowed
Broadcast Suppression Level: 100Multicast Suppression Level: 70Unicast Suppression Level: 100
Configuring Layer 2 EtherChannels: Example• Layer 2 EtherChannels: Example, page 332
• Removing an EtherChannel: Example, page 332
Layer 2 EtherChannels: Example
The following example shows Fast Ethernet interfaces 5/6 and 5/7 being configured into port-channel 2 and forces the port to channel without Port Aggregation Protocol (PAgP). The EtherChannel is configured to use source and destination IP addresses.
Router# configure terminal Router(config)# interface range fastethernet 5/6 - 7 Router(config-if)# channel-group 2 mode on Router(config-if)# exit Router(config)# port-channel load-balance src-dst-ip
Removing an EtherChannel: Example
The following example shows port-channel 1 being removed:
Router# configure terminal Router(config)# no interface port-channel 1 Router(config)# end
Note Removing the port-channel also removes the channel-group command from the interfaces belonging to it.
Configuring Flow Control on Gigabit Ethernet Ports: ExampleThe following examples show how to turn transmit and receive flow control on and how to verify the flow-control configuration.
Port 4/0 flow control send administration status is set to on (port will send flowcontrol to far end):
Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface gigabitethernet4/0Router(config-if)# flowcontrol send onRouter(config-if)# end
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Port 4/0 flow control receive administration status is set to on (port will require far end to send flowcontrol):
Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface gigabitethernet4/0Router(config-if)# flowcontrol receive onRouter(config-if)# end
The following example shows flow control configuration being verified:
Router# show interface gigabitethernet4/0GigabitEthernet4/0 is up, line protocol is up Hardware is Gigabit Ethernet, address is 0087.c08b.4824 (bia0087.c08b.4824) MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) output flow-control is off, input flow-control is on 0 pause input, 0 pause output Full-duplex, 1000Mb/s ARP type:ARPA, ARP Timeout 04:00:00 Last input 00:00:01, output never, output hang never Last clearing of "show interface" counters never Input queue:0/75/0/0 (size/max/drops/flushes); Total output drops:0 Queueing strategy:fifo Output queue:0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 1 packets/sec 398301 packets input, 29528679 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 input packets with dribble condition detected 790904 packets output, 54653461 bytes, 0 underruns 0 output errors, 0 collisions, 5 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out
The following example shows how to configure Gigabit Ethernet interface 0/10 as a routed port and to assign it an IP address:
Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface gigabitethernet0/10Router(config-if)# no switchportRouter(config-if)# ip address 10.1.2.3 255.255.0.0Router(config-if)# no shutdownRouter(config-if)# end
The following is sample output from the show interfaces privileged EXEC command for Gigabit Ethernet interface 0/2:
Router# show interfaces gigabitethernet0/2GigabitEthernet0/2 is up, line protocol is up Hardware is Gigabit Ethernet, address is 0002.4b29.4400 (bia 0002.4b29.4400) Internet address is 192.168.135.21/24 MTU 1500 bytes, BW 100000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 100Mb/s input flow-control is off, output flow-control is off
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ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:02, output 00:00:08, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 89604 packets input, 8480109 bytes, 0 no buffer Received 81848 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 input packets with dribble condition detected 60665 packets output, 6029820 bytes, 0 underruns 0 output errors, 0 collisions, 16 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out
The following is sample output from the show ip interface privileged EXEC command for Gigabit Ethernet interface 0/2:
Router# show ip interface gigabitethernet0/2GigabitEthernet0/2 is up, line protocol is up Internet address is 192.168.135.21/24 Broadcast address is 255.255.255.255 Address determined by setup command MTU is 1500 bytes Helper address is not set Directed broadcast forwarding is disabled Multicast reserved groups joined: 224.0.0.5 224.0.0.6 Outgoing access list is not set Inbound access list is not set Proxy ARP is enabled Local Proxy ARP is disabled Security level is default Split horizon is enabled ICMP redirects are always sent ICMP unreachables are always sent ICMP mask replies are never sent IP fast switching is enabled IP fast switching on the same interface is disabled IP Flow switching is disabled IP CEF switching is enabled IP CEF Fast switching turbo vector IP multicast fast switching is enabled IP multicast distributed fast switching is disabled IP route-cache flags are Fast, CEF Router Discovery is disabled IP output packet accounting is disabled IP access violation accounting is disabled TCP/IP header compression is disabledRTP/IP header compression is disabled Probe proxy name replies are disabled Policy routing is disabled Network address translation is disabled WCCP Redirect outbound is disabled WCCP Redirect exclude is disabled BGP Policy Mapping is disabled
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The following is sample output from the show running-config privileged EXEC command for Gigabit Ethernet interface 0/2:
Router# show running-config interface gigabitethernet0/2 Building configuration...
Current configuration : 122 bytes!interface GigabitEthernet0/2 no switchport ip address 192.168.135.21 255.255.255.0 speed 100 mls qos trust dscpend
Intrachassis Stacking: ExampleThe following example shows how to stack GE port 2/0 to GE port 3/0 to form an extended VLAN within one chassis:
Router# config terminal Router(config)# interface Gigabit 2/0 Router(config-if)# switchport stacking-link interface Gigabit3/0
The following example shows interchassis stacking being verified between GE port 2/0 and GE port 3/0:
Router# show interface gigabit 2/0
GigabitEthernet2/0 is up, line protocol is down Internal Stacking Link Active : Gi2/0 is stacked with Gi3/0 Hardware is Gigabit Ethernet, address is 001b.3f2b.2c24 (bia 001b.3f2b.2c24) MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex mode, link type is force-up, media type is unknown 0 output flow-control is off, input flow-control is off Full-duplex, 1000Mb/s ARP type: ARPA, ARP Timeout 04:00:00 Last input 1d22h, output never, output hang never Last clearing of "show interface" counters 1d22h Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 250707 packets input, 19562597 bytes, 0 no buffer Received 7 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 0 multicast, 0 pause input 0 input packets with dribble condition detected 7469804 packets output, 582910831 bytes, 0 underruns(0/0/0) 0 output errors, 0 collisions, 0 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier, 0 pause output 0 output buffer failures, 0 output buffers swapped out
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Configuring Switched Port Analyzer (SPAN): ExampleThe following example shows SPAN session 1 being configured to monitor bidirectional traffic from source interface Fast Ethernet 5/1. Fast Ethernet interface 5/48 is configured as the destination for SPAN session 1 and Fast Ethernet interface 5/2 is removed as a SPAN source for SPAN session 1.
Router(config)# monitor session 1 source interface fastethernet 5/1Router(config)# monitor session 1 destination interface fastethernet 5/48Router(config)# no monitor session 1 source interface fastethernet 5/2
Configuring Layer 3 Interfaces: ExampleThe following example shows how to configure Gigabit Ethernet interface 0/10 as a routed port and to assign it an IP address:
Router# configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router(config)# interface gigabitethernet0/10Router(config-if)# no switchportRouter(config-if)# ip address 10.1.2.3 255.255.0.0Router(config-if)# no shutdownRouter(config-if)# end
The following is sample output from the show interfaces privileged EXEC command for Gigabit Ethernet interface 0/2:
Router# show interfaces gigabitethernet0/2
GigabitEthernet0/2 is up, line protocol is up Hardware is Gigabit Ethernet, address is 0002.4b29.4400 (bia 0002.4b29.4400) Internet address is 192.168.135.21/24 MTU 1500 bytes, BW 100000 Kbit, DLY 10 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 100Mb/s input flow-control is off, output flow-control is off ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:02, output 00:00:08, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 89604 packets input, 8480109 bytes, 0 no buffer Received 81848 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 input packets with dribble condition detected 60665 packets output, 6029820 bytes, 0 underruns 0 output errors, 0 collisions, 16 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out
The following is sample output from the show ip interface privileged EXEC command for Gigabit Ethernet interface 0/2:
Router# show ip interface gigabitethernet0/2GigabitEthernet0/2 is up, line protocol is up Internet address is 192.168.135.21/24 Broadcast address is 255.255.255.255
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Address determined by setup command MTU is 1500 bytes Helper address is not set Directed broadcast forwarding is disabled Multicast reserved groups joined: 224.0.0.5 224.0.0.6 Outgoing access list is not set Inbound access list is not set Proxy ARP is enabled Local Proxy ARP is disabled Security level is default Split horizon is enabled ICMP redirects are always sent ICMP unreachables are always sent ICMP mask replies are never sent IP fast switching is enabled IP fast switching on the same interface is disabled IP Flow switching is disabled IP CEF switching is enabled IP CEF Fast switching turbo vector IP multicast fast switching is enabled IP multicast distributed fast switching is disabled IP route-cache flags are Fast, CEF Router Discovery is disabled IP output packet accounting is disabled IP access violation accounting is disabled TCP/IP header compression is disabled RTP/IP header compression is disabled Probe proxy name replies are disabled Policy routing is disabled Network address translation is disabled WCCP Redirect outbound is disabled WCCP Redirect exclude is disabled BGP Policy Mapping is disabled
The following is sample output from the show running-config privileged EXEC command for Gigabit Ethernet interface 0/2:
Router# show running-config interface gigabitethernet0/2 Building configuration...
Current configuration : 122 bytes!interface GigabitEthernet0/2 no switchport ip address 192.168.135.21 255.255.255.0 speed 100 mls qos trust dscpend
IGMP Snooping: Example
Default IGMP Snooping Configuration
IGMP snooping is enabled by default on a VLAN or subnet basis. Multicast routing has to be enabled on the router first and then PIM (Multicast routing protocol) has to be enabled on the VLAN interface so that the EtherSwitch network module acknowledges the IGMP join and leave messages that are sent from the hosts connected to the EtherSwitch network module.
Router(config)# ip multicast-routingRouter(config-if)# interface VLAN1Router(config-if)# ip-address 192.168.10.1 255.255.255.0Router(config-if)# ip pim sparse-mode
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The following example shows the output from configuring IGMP snooping:
Router# show mac-address-table multicast igmp-snooping
Slot # :3 -------------- MACADDR VLANID INTERFACES
0100.5e00.0001 1 0100.5e00.0002 1 0100.5e00.000d 1 0100.5e00.0016 1 0100.5e05.0505 1 Fa3/12 0100.5e06.0606 1 Fa3/13 0100.5e7f.ffff 1 Fa3/13 0100.5e00.0001 2 0100.5e00.0002 2 0100.5e00.000d 2 0100.5e00.0016 2 0100.5e00.0128 2 0100.5e05.0505 2 Fa3/10 0100.5e06.0606 2 Fa3/11
The following example shows output from the show running-config interface privileged EXEC command for VLAN 1:
Router# show running-config interface vlan 1
Building configuration...
Current configuration :82 bytes ! interface Vlan1 ip address 192.168.4.90 255.255.255.0 ip pim sparse-mode end
The following example shows output from the show running-config interface privileged EXEC command for VLAN 2:
Router# show running-config interface vlan 2
Building configuration...
Current configuration :82 bytes ! interface Vlan2 ip address 192.168.5.90 255.255.255.0 ip pim sparse-mode end
The following example shows output verifying multicasting support:
Router# show ip igmp group
IGMP Connected Group Membership Group Address Interface Uptime Expires Last Reporter 239.255.255.255 Vlan1 01:06:40 00:02:20 192.168.41.101 224.0.1.40 Vlan2 01:07:50 00:02:17 192.168.5.90 224.5.5.5 Vlan1 01:06:37 00:02:25 192.168.41.100 224.5.5.5 Vlan2 01:07:40 00:02:21 192.168.31.100 224.6.6.6 Vlan1 01:06:36 00:02:22 192.168.41.101 224.6.6.6 Vlan2 01:06:39 00:02:20 192.168.31.101
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The following example shows output from the multicast routing table:
Router# show ip mroute
IP Multicast Routing Table Flags:D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected, L - Local, P - Pruned, R - RP-bit set, F - Register flag, T - SPT-bit set, J - Join SPT, M - MSDP created entry, X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement, U - URD, I - Received Source Specific Host Report Outgoing interface flags:H - Hardware switched Timers:Uptime/Expires Interface state:Interface, Next-Hop or VCD, State/Mode
(*, 239.255.255.255), 01:06:43/00:02:17, RP 0.0.0.0, flags:DC Incoming interface:Null, RPF nbr 0.0.0.0 Outgoing interface list: Vlan1, Forward/Sparse, 01:06:43/00:02:17
(*, 224.0.1.40), 01:12:42/00:00:00, RP 0.0.0.0, flags:DCL Incoming interface:Null, RPF nbr 0.0.0.0 Outgoing interface list: Vlan2, Forward/Sparse, 01:07:53/00:02:14
(*, 224.5.5.5), 01:07:43/00:02:22, RP 0.0.0.0, flags:DC Incoming interface:Null, RPF nbr 0.0.0.0 Outgoing interface list: Vlan1, Forward/Sparse, 01:06:40/00:02:22 Vlan2, Forward/Sparse, 01:07:44/00:02:17
(*, 224.6.6.6), 01:06:43/00:02:18, RP 0.0.0.0, flags:DC Incoming interface:Null, RPF nbr 0.0.0.0 Outgoing interface list: Vlan1, Forward/Sparse, 01:06:40/00:02:18 Vlan2, Forward/Sparse, 01:06:43/00:02:16
Configuring Fallback Bridging: ExamplesThis section contains the following examples:
• Creating a Bridge Group: Example, page 339
• Adjusting Spanning Tree Parameters: Example, page 340
• Disabling the Spanning Tree on an Interface: Example, page 340
• Fallback Bridging with DLSW: Example, page 340
Creating a Bridge Group: Example
The following example shows how to create bridge group 10, specify the VLAN-bridge STP to run in the bridge group, and assign an interface to the bridge group. The switch device is prevented from forwarding frames for stations that it has dynamically learned in bridge group 10, and the bridge table aging time is set to 200 seconds. Frames with a MAC address of 0800.cb00.45e9 are forwarded through an interface in bridge group 1.
Router(config)# bridge 10 protocol vlan-bridgeRouter(config)# interface gigabitethernet0/1Router(config-if)# no switchport
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Router(config-if)# bridge-group 10Router(config-if)# exitRouter(config)# no bridge 10 acquireRouter(config)# bridge 10 aging-time 200Router(config)# bridge 1 address 0800.cb00.45e9 forward gigabitethernet0/1
Adjusting Spanning Tree Parameters: Example
The following example shows how to set the switch priority to 100 for bridge group 10, how to change the priority of an interface to 20 in bridge group 10, and how to change the path cost on an interface to 20 in bridge group 10. In bridge group 10 the hello interval is changed to 5 seconds, the forward-delay interval is changed to 10 seconds, and the maximum-idle interval to 30 seconds.
Router(config)# bridge 10 priority 100Router(config)# interface gigabitethernet0/1Router(config-if)# bridge-group 10 priority 20Router(config-if)# bridge-group 10 path-cost 20Router(config)# bridge 10 hello-time 5Router(config)# bridge 10 forward-time 10Router(config)# bridge 10 max-age 30
Disabling the Spanning Tree on an Interface: Example
The following example shows how to disable spanning tree on an interface in bridge group 10:
Router(config)# interface gigabitethernet0/1Router(config-if)# bridge group 10 spanning-disabled
Fallback Bridging with DLSW: Example
The following example shows how to configure fallback bridging with DLSW on the EtherSwitch network module. Using the network in Figure 40 this example shows how to bridge VLANs over routers. Normally VLANs terminate at a router. Note that both PCs are on the same subnet although they are actually separated by two routers. The fallback bridging creates a virtual bridge between the two PCs.
Figure 40 Fallback Bridging with DLSW Network Example
The following are partial configurations for Router A and Router B:
Router Ano spanning-tree vlan 1no spanning-tree vlan 100!bridge irb!
1556
79WAN
10.80.112.10 10.80.112.11
FE 1/8VLAN100172.17.2.1
Serial 0/1 Serial 0/1
172.17.2.2FE 1/8
VLAN100
Interface VLAN 100No IP Address
Interface VLAN 100No IP Address
Cisco router with Ethernetswitch network module
Interface VLAN 1192.168.65.1
Interface VLAN 1192.168.65.2
Interface VLAN 1192.168.65.1
Interface VLAN 1192.168.65.2
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dlsw local-peer peer-id 192.168.65.1dlsw remote-peer 0 tcp 192.168.66.1dlsw bridge-group 1!interface FastEthernet1/8 switchport access vlan 100 no ip address!interface Vlan1 ip address 192.168.65.1 255.255.255.0!interface Vlan100 no ip address bridge-group 1 bridge-group 1 spanning-disabled!bridge 1 protocol ieeecall rsvp-sync
Router Bno spanning-tree vlan 1no spanning-tree vlan 100!bridge irb!dlsw local-peer peer-id 192.168.66.1dlsw remote-peer 0 tcp 192.168.65.1dlsw bridge-group 1!interface FastEthernet1/8 switchport access vlan 100 no ip addressinterface Vlan1 ip address 192.168.65.2 255.255.255.0!interface Vlan100 no ip address bridge-group 1 bridge-group 1 spanning-disabled!bridge 1 protocol ieeecall rsvp-sync
Configuring Network Security with ACLs at Layer 2: Examples• Creating Numbered Standard and Extended ACLs: Example, page 342
• Creating Named Standard and Extended ACLs: Example, page 342
• Including Comments About Entries in ACLs: Example, page 343
• Applying the ACL to an Interface: Example, page 343
• Displaying Standard and Extended ACLs: Example, page 343
• Displaying Access Groups: Example, page 344
• Compiling ACLs: Example, page 345
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Creating Numbered Standard and Extended ACLs: Example
The following example shows how to create a standard ACL to deny access to IP host 172.19.198.102, permit access to any others, and display the results:
Switch (config)# access-list 2 deny host 172.19.198.102Switch (config)# access-list 2 permit anyRouter(config)# end Router# show access-lists
Standard IP access list 2 deny 172.19.198.102 permit any
The following example shows that the switch accepts addresses on network 10.0.0.0 subnets and denies all packets coming from 10.10.0.0 subnets. The ACL is then applied to packets entering Gigabit Ethernet interface 0/1:
Router(config)# access-list 2 permit 10.0.0.0 0.255.255.255Router(config)# access-list 2 deny 10.10.0.0 0.255.255.255Router(config)# interface gigabitethernet0/1Router(config-if)# ip access-group 2 in
The following example shows how to create and display an extended access list to deny Telnet access from any host in network 172.16.198.0 to any host in network 192.168.52.0 and permit any others (the eq keyword after the destination address means to test for the TCP destination port number equaling Telnet):
Router(config)# access-list 102 deny tcp 172.16.198.0 0.0.0.255 192.168.52.0 0.0.0.255 eq telnetRouter(config)# access-list 102 permit tcp any any Router(config)# end Router# show access-lists
Extended IP access list 102 deny tcp 172.16.198.0 0.0.0.255 192.168.52.0 0.0.0.255 eq telnet permit tcp any any
The following example shows an extended ACL with a network connected to the Internet and any host on the network being able to form TCP Telnet and SMTP connections to any host on the Internet:
Router(config)# access-list 102 permit tcp any 172.18.0.0 0.0.255.255 eq 23Router(config)# access-list 102 permit tcp any 172.18.0.0 0.0.255.255 eq 25Router(config)# interface gigabitethernet0/1Router(config-if)# ip access-group 102 in
SMTP uses TCP port 25 on one end of the connection and a random port number on the other end. The same port numbers are used throughout the life of the connection. Mail packets coming in from the Internet have a destination port of 25. Because the secure system behind the switch always accepts mail connections on port 25, the incoming services are controlled.
Creating Named Standard and Extended ACLs: Example
The following example shows how you can delete individual ACEs from a named ACL:
Router(config)# ip access-list extended border-listRouter(config-ext-nacl)# no permit ip host 10.1.1.3 any
The following example shows the marketing_group ACL allowing any TCP Telnet traffic to the destination address and wildcard 172.19.0.0 0.0.255.255 and denying any other TCP traffic. It permits any other IP traffic:
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Router(config)# ip access-list extended marketing_groupRouter(config-ext-nacl)# permit tcp any 172.19.0.0 0.0.255.255 eq telnetRouter(config-ext-nacl)# deny tcp any anyRouter(config-ext-nacl)# permit ip any any
The ACLs are applied to permit Gigabit Ethernet port 0/1, which is configured as a Layer 2 port, with the marketing_group ACL applied to incoming traffic.
Router(config)# interface gigabitethernet0/1Router(config-if)# ip access-group marketing_group in
Including Comments About Entries in ACLs: Example
The following example shows an IP numbered standard ACL using the access-list access-list number remark remark global configuration command to include a comment about an access list. In this example, the workstation belonging to Jones is allowed access, and the workstation belonging to Smith is not allowed access:
Router(config)# access-list 1 remark Permit only Jones workstation throughRouter(config)# access-list 1 permit 172.19.2.88Router(config)# access-list 1 remark Do not allow Smith workstation throughRouter(config)# access-list 1 deny 172.19.3.13
The following example shows an entry in a named IP ACL using the remark access-list global configuration command to include a comment about an access list. In this example, the Jones subnet is not allowed to use outbound Telnet:
Router(config)# ip access-list extended telnettingRouter(config-ext-nacl)# remark Do not allow Jones subnet to telnet outRouter(config-ext-nacl)# deny tcp host 172.19.2.88 any eq telnet
In this example of a numbered ACL, the workstation belonging to Jones is allowed access, and the workstation belonging to Smith is not allowed access:
Router(config)# access-list 1 remark Permit only Jones workstation throughRouter(config)# access-list 1 permit 172.19.2.88Router(config)# access-list 1 remark Do not allow Smith workstation throughRouter(config)# access-list 1 deny 172.19.3.13
In this example of a numbered ACL, the Winter and Smith workstations are not allowed to browse the web:
Router(config)# access-list 100 remark Do not allow Winter to browse the webRouter(config)# access-list 100 deny host 172.19.3.85 any eq wwwRouter(config)# access-list 100 remark Do not allow Smith to browse the webRouter(config)# access-list 100 deny host 172.19.3.13 any eq www
Applying the ACL to an Interface: Example
The following example shows how to apply access list 2 on Gigabit Ethernet interface 0/3 to filter packets entering the interface:
Router(config)# interface gigabitethernet0/3Router(config-if)# ip access-group 2 in
Displaying Standard and Extended ACLs: Example
The following example displays all standard and extended ACLs:
Router# show access-lists
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Standard IP access list 1 permit 172.20.10.10Standard IP ACL 10 permit 10.12.12.12Standard IP access list 12 deny 10.3.3.2Standard IP access list 32 permit 172.20.20.20Standard IP access list 34 permit 10.24.35.56 permit 10.45.56.34Extended IP access list 120
The following example displays only IP standard and extended ACLs:
Router# show ip access-listsStandard IP access list 1 permit 172.20.10.10Standard IP access list 10 permit 10.12.12.12Standard IP access list 12 deny 10.3.3.2Standard IP access list 32 permit 172.20.20.20Standard IP access list 34 permit 10.24.35.56 permit 10.45.56.34Extended IP access list 120
Displaying Access Groups: Example
You use the ip access-group interface configuration command to apply ACLs to a Layer 3 interface. When IP is enabled on an interface, you can use the show ip interface interface-id privileged EXEC command to view the input and output access lists on the interface, as well as other interface characteristics. If IP is not enabled on the interface, the access lists are not shown.
The following example shows how to view all access groups configured for VLAN 1 and for Gigabit Ethernet interface 0/2:
Router# show ip interface vlan 1GigabitEthernet0/2 is up, line protocol is down Internet address is 10.20.30.1/16 Broadcast address is 255.255.255.255 Address determined by setup command MTU is 1500 bytes Helper address is not set Directed broadcast forwarding is disabled Outgoing access list is permit Any Inbound access list is 13...
Router# show ip interface fastethernet 0/9FastEthernet0/9 is down, line protocol is down Inbound access list is ip1
The only way to ensure that you can view all configured access groups under all circumstances is to use the show running-config privileged EXEC command. To display the ACL configuration of a single interface, use the show running-config interface interface-id command.
The following example shows how to display the ACL configuration of Gigabit Ethernet interface 0/1:
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Router# show running-config interface gigabitethernet0/1Building configuration...
Current configuration :112 bytes!interface GigabitEthernet0/1 ip access-group 11 in snmp trap link-status no cdp enableend
Compiling ACLs: Example
For detailed information about compiling ACLs, refer to the Security Configuration Guide and the “IP Services” chapter of the Cisco IOS IP and IP Routing Configuration Guide.
Figure 41 shows a small networked office with a stack of Catalyst 2950 switches that are connected to a Cisco router with an EtherSwitch network module installed. A host is connected to the network through the Internet using a WAN link.
Use switch ACLs to do these tasks:
• Create a standard ACL, and filter traffic from a specific Internet host with an address 172.20.128.64.
• Create an extended ACL, and filter traffic to deny HTTP access to all Internet hosts but allow all other types of access.
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Figure 41 Using Switch ACLs to Control Traffic
The following example uses a standard ACL to allow access to a specific Internet host with the address 172.20.128.64:
Router(config)# access-list 6 permit 172.20.128.64 0.0.0.0Router(config)# endRouter(config)# interface gigabitethernet0/1Router(config-if)# ip access-group 6 in
The following example uses an extended ACL to deny traffic from port 80 (HTTP). It permits all other types of traffic:
Router(config)# access-list 106 deny tcp any any eq 80Router(config)# access-list 106 permit ip any anyRouter(config)# interface gigabitethernet0/2Router(config-if)# ip access-group 106 in
Configuring QoS on the EtherSwitch network module: Examples• Classifying Traffic by Using ACLs: Example, page 347
• Classifying Traffic by Using Class Maps: Example, page 347
Cisco router with Ethernetswitch network module
Catalyst 2950
Catalyst 2950
Workstation
Endworkstations 15
5692
Internet
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• Classifying, Policing, and Marking Traffic by Using Policy Maps: Example, page 347
• Configuring the CoS-to-DSCP Map: Example, page 347
• Configuring the DSCP-to-CoS Map: Example, page 348
• Displaying QoS Information: Example, page 348
Classifying Traffic by Using ACLs: Example
The following example shows how to allow access for only those hosts on the two specified networks. The wildcard bits apply to the host portions of the network addresses. Any host with a source address that does not match the ACL statements is rejected.
Router(config)# access-list 1 permit 172.25.255.0 0.0.0.255Router(config)# access-list 1 permit 172.16.0.0 0.0.0.255
Classifying Traffic by Using Class Maps: Example
The following example shows how to configure the class map called class1. The class1 has one match criterion, which is an ACL called 103.
Router(config)# access-list 103 permit any any tcp eq 80 Router(config)# class-map class1Router(config-cmap)# match access-group 103Router(config-cmap)# endRouter#
Classifying, Policing, and Marking Traffic by Using Policy Maps: Example
The following example shows how to create a policy map and attach it to an ingress interface. In the configuration, the IP standard ACL permits traffic from network 10.1.0.0. For traffic matching this classification, the DSCP value in the incoming packet is trusted. If the matched traffic exceeds an average traffic rate of 48000 bps and a normal burst size of 8000 bytes, its DSCP is marked down to a value of 10 and transmitted.
Router(config)# access-list 1 permit 10.1.0.0 0.0.255.255Router(config)# class-map ipclass1Router(config-cmap)# match access-group 1Router(config-cmap)# exitRouter(config)# policy-map flow1tRouter(config-pmap)# class ipclass1Router(config-pmap-c)# police 5000000 8192 exceed-action dscp 10Router(config-pmap-c)# exitRouter(config-pmap)# exitRouter(config)# interface gigabitethernet0/1Router(config-if)# switchport mode accessRouter(config-if)# service-policy input flow1t
Configuring the CoS-to-DSCP Map: Example
The following example shows how to modify and display the CoS-to-DSCP map:
Router# configure terminalRouter(config)# mls qos map cos-dscp 8 8 8 8 24 32 56 56Router(config)# endRouter# show mls qos maps cos-dscp
Cos-dscp map:
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cos: 0 1 2 3 4 5 6 7 -------------------------------- dscp: 8 8 8 8 24 32 56 56
Configuring the DSCP-to-CoS Map: Example
The following example shows how the DSCP values 26 and 48 are mapped to CoS value 7. For the remaining DSCP values, the DSCP-to-CoS mapping is the default.
Router(config)# mls qos map dscp-cos 26 48 to 7Router(config)# exit
Router# show mls qos maps dscp-cos
Dscp-cos map: dscp: 0 8 10 16 18 24 26 32 34 40 46 48 56 ----------------------------------------------- cos: 0 1 1 2 2 3 7 4 4 5 5 7 7
Displaying QoS Information: Example
The following example shows how to display the DSCP-to-CoS maps:
Router# show mls qos maps dscp-cos
Dscp-cos map: dscp: 0 8 10 16 18 24 26 32 34 40 46 48 56 ----------------------------------------------- cos: 0 1 1 2 2 3 3 4 4 5 5 6 7
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Additional ReferencesThe following sections provide references related to the EtherSwitch network module.
Related Documents
Standards
Related Topic Document Title
Quick Start Guide for the Cisco 2600 series Cisco 2600 Series Modular Routers Quick Start Guide
Hardware installation for the Cisco 2600 series Cisco 2600 Series Hardware Installation Guide
Quick Start Guide for the Cisco 3600 series Quick start guides for Cisco 3600 series routers
Hardware installation for the Cisco 3600 series Cisco 3600 Series Hardware Installation Guide
Quick Start Guide for the Cisco 3700 series Quick start guides for Cisco 3700 series routers
Hardware installation for the Cisco 3700 series Hardware installation documents for Cisco 3700 series routers
Information about configuring Voice over IP features Cisco IOS Voice, Video, and Fax Configuration Guide
Voice over IP commands Cisco IOS Voice, Video, and Fax Command Reference, Release 12.3 T
Information about Flow Control Configuring Gigabit Ethernet Switching
Standards Title
802.1d Spanning Tree Protocol
802.1p Supplement to MAC Bridges: Traffic Class Expediting and Dynamic Multicast Filtering
802.1q Virtual LAN (VLAN) Bridges
802.1x Port Based Network Access Control
EtherSwitch Network ModuleAdditional References
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MIBs
RFCs
MIBs MIBs Link
• IF MIB
• CISCO-CDP-MIB
• CISCO-CDP-MIB
• CISCO-IMAGE-MIB
• CISCO-FLASH-MIB
• OLD-CISCO-CHASSIS-MIB
• CISCO-VTP-MIB
• CISCO-HSRP-MIB
• OLD-CISCO-TS-MIB
• CISCO-ENTITY-ASSET-MIB
• CISCO-ENTITY-FRU-CONTROL-MIB
• CISCO-ENTITY-ASSET-MIB
• CISCO-VLAN-MEMBERSHIP-MIB
• CISCO-VLAN-IFINDEX-RELATIONSHIP-MIB
• RMON1-MIB
• PIM-MIB
• CISCO-STP-EXTENSIONS-MIB
• IPMROUTE-MIB
• CISCO-MEMORY-POOL-MIB
• CISCO-RTTMON-MIB
• CISCO-PROCESS-MIB
• CISCO-COPS-CLIENT-MIB
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL:
http://www.cisco.com/go/mibs
RFCs Title
RFC 1213 Management Information Base for Network Management of TCP/IP-Based Internets, MIB-II
RFC 1253 OSPF Version 2 Management Information Base
RFC 1493 Definitions of Managed Objects for Bridges
RFC 1643 Definitions of Managed Objects for the Ethernet-Like Interface Types
RFC 2037 Entity MIB using SMIv2
RFC 2284 PPP Extensible Authentication Protocol (EAP)
EtherSwitch Network ModuleCommand Reference
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Technical Assistance
Command ReferenceThe following new and modified commands are pertinent to this feature. To see the command pages for these commands and other commands used with this feature, go to the Cisco IOS Master Commands List, Release 12.4, at http://www.cisco.com/univercd/cc/td/doc/product/software/ios124/124mindx/124index.htm.
• aaa authentication dot1x
• class (EtherSwitch)
• debug dot1x (EtherSwitch)
• debug eswilp
• debug ip igmp snooping
• debug spanning-tree
• dot1x default
• dot1x max-req
• dot1x multiple-hosts
• dot1x port-control
• dot1x re-authenticate (EtherSwitch)
• dot1x re-authentication
• dot1x timeout (EtherSwitch)
• ip igmp snooping
• ip igmp snooping vlan
• ip igmp snooping vlan immediate-leave
• ip igmp snooping vlan mrouter
• ip igmp snooping vlan static
• mls qos cos
• mls qos map
• mls qos trust
• police (EtherSwitch)
• show dot1x (EtherSwitch)
• show ip igmp snooping
Description Link
Technical Assistance Center (TAC) home page, containing 30,000 pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.
http://www.cisco.com/public/support/tac/home.shtml
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• show ip igmp snooping mrouter
• show mls masks
• show mls qos interface
• show mls qos maps
• show spanning-tree
• show storm-control
• spanning-tree backbonefast
• storm-control
• switchport
EtherSwitch Network ModuleGlossary
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Glossary802.1d—IEEE standard for MAC bridges.
802.1p—IEEE standard for queuing and multicast support.
802.1q—IEEE standard for VLAN frame tagging.
802.1x—IEEE standard for port-based network access control.
ACE—access control entry. Entry in an access control list.
ACL—access control list. Used for security or as a general means to classify traffic.
AgPort—aggregate port (another name for EtherChannel).
ATM—Asynchronous Transfer Mode. The international standard for cell relay in which multiple service types (such as voice, video, or data) are conveyed in fixed-length (53-byte) cells. Fixed-length cells allow cell processing to occur in hardware, thereby reducing transit delays. ATM is designed to take advantage of high-speed transmission media such as E3, SONET, and T3.
authentication server—Entity that validates the credentials of a host trying to obtain access to the network.
authenticator—Entity that enforces authentication rules for hosts connecting to a LAN via one of its ports.
authorization state—The state of a controlled port. It can be authorized (access allowed) or unauthorized (access denied).
AVVID—Architecture for voice, video, and integrated data.
BRI—Basic Rate Interface. ISDN interface comprising two B channels and one D channel for circuit-switched communication of voice, video, and data.
CAC—connection admission control. Set of actions taken by each ATM switch during connection setup to determine whether a connection’s requested QoS will violate the QoS guarantees for established connections. CAC is also used when routing a connection request through an ATM network.
candidate—Switch that is not part of a cluster, but is eligible to join a cluster because it meets the qualification criteria of the cluster.
CBWFQ—class-based weighted fair queuing. Extends the standard WFQ functionality to provide support for user-defined traffic classes.
CCN—Cisco Communications Network (Cisco IP phones and IP PBX).
classification—Process of sorting incoming packets by examining fields of interest in the packet header. Fields can be addresses, ports, DSCP value, and so on.
cluster—Group of switches that are managed as a single device. A cluster comprises one commander and multiple members.
cluster commander—Switch that provides the primary management interface to a cluster.
cluster member—Member switch that is managed through the cluster commander.
CoS—class of service. An indication of how an upper-layer protocol requires a lower-layer protocol to treat its messages. In SNA subarea routing, CoS definitions are used by subarea nodes to determine the optimal route to establish a session. A CoS definition comprises a virtual route number and a transmission priority field. Also called ToS.
DSCP—differentiated services code point. In QoS, a modification of the type of service byte. Six bits of this byte are being reallocated for use as the DSCP field, where each DSCP specifies a particular per-hop behavior that is applied to a packet.
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DSL—digital subscriber line. Public network technology that delivers high bandwidth over conventional copper wiring at limited distances. There are four types of DSL: ADSL, HDSL, SDSL, and VDSL. All are provisioned via modem pairs, with one modem at a central office and the other at the customer site. Because most DSL technologies do not use the whole bandwidth of the twisted pair, there is room remaining for a voice channel.
EAP—Extensible Authentication Protocol. A mechanism (originally designed for PPP in RFC 2284) that provides authentication of hosts requesting access to a network.
EAPOL—EAP over LAN.
Frame Relay—The capability to carry normal telephony-style voice over an IP-based network with POTS-like functionality, reliability, and voice quality. VoIP lets a router carry voice traffic (such as telephone calls and faxes) over an IP network. In VoIP, the DSP segments the voice signal into frames, which then are coupled in groups of two and stored in voice packets. These voice packets are transported using IP in compliance with ITU-T specification H.323.
FXO—Foreign Exchange Office. An FXO interface connects to the Public Switched Telephone Network (PSTN) central office and is the interface offered on a standard telephone. Cisco’s FX interface is an RJ-11 connector that allows an analog connection at the PSTN’s central office or to a station interface on a PBX.
FXS—Foreign Exchange Station. An FXS interface connects directly to a standard telephone and supplies ring, voltage, and dial tone. Cisco’s FXS interface is an RJ-11 connector that allows connections to basic telephone service equipment, keysets, and PBXs.
HSRP—Hot Standby Router Protocol. Provides high network availability and transparent network topology changes. HSRP creates a hot standby router group with a lead router that services all packets sent to the hot standby address. The lead router is monitored by other routers in the group, and if it fails, one of these standby routers inherits the lead position and the hot standby group address.
IGMP—Internet Group Management Protocol. Used by IP hosts to report their multicast group memberships to an adjacent multicast router.
ISL—InterSwitch Link, which is used to carry traffic for multiple VLANs. A method of encapsulating tagged LAN frames and transporting them over a full-duplex, point-to-point Ethernet link. The encapsulated frames can be Token Ring or Fast Ethernet and are carried unchanged from transmitter to receiver.
MIB—Management Information Base. Database of network management information that is used and maintained by a network management protocol, such as SNMP or Common Management Information Protocol (CMIP). The value of a MIB object can be changed or retrieved using SNMP or CMIP commands, usually through a graphical user interface (GUI) network management system. MIB objects are organized in a tree structure that includes public (standard) and private (proprietary) branches.
policing—Process of ensuring whether a stream of classified incoming packets conforms to a particular traffic profile. An action (drop or remark) is taken based on the rate of arrival of packets.
PRI—primary rate interface. ISDN interface to primary rate access. Primary rate access consists of one 64-kbps D channel and 23 (T1) or 30 (E1) B channels for voice or data. Compare with BRI.
PSTN—public switched telephone network. General term referring to the variety of telephone networks and services in place worldwide. Also called POTS.
PVC—permanent virtual circuit. Virtual circuit that is permanently established. PVCs save bandwidth associated with circuit establishment and tear down in situations where certain virtual circuits must exist all the time. In ATM terminology, called a permanent virtual connection.
PVST—Per-VLAN spanning tree. Support for dot1q trunks to map multiple spanning trees to a single spanning tree.
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QoS—quality of service. Measure of performance for a transmission system that reflects its transmission quality and service availability.
RADIUS—Remote Access Dial-In User Service. A service used to authenticate and authorize clients.
RMON—remote monitoring. MIB agent specification described in RFC 1271 that defines functions for the remote monitoring of networked devices. The RMON specification provides numerous monitoring, problem detection, and reporting capabilities.
RSVP—Resource Reservation Protocol. Protocol that supports the reservation of resources across an IP network. Applications running on IP end systems can use RSVP to indicate to other nodes the nature (bandwidth, jitter, maximum burst, and so on) of the packet streams they want to receive. RSVP depends on IPv6. Also known as Resource Reservation Setup Protocol.
SIP—Session Initiation Protocol. Protocol developed by the IETF MMUSIC Working Group as an alternative to H.323. SIP features are compliant with IETF RFC 2543, which was published in March 1999. SIP equips platforms to signal the setup of voice and multimedia calls over IP networks.
SNMP—Simple Network Management Protocol. Network management protocol used almost exclusively in TCP/IP networks. SNMP provides a means to monitor and control network devices and to manage configurations, statistics collection, performance, and security.
stacking—Connecting two switches so they behave as one entity for management purposes. Regarding an EtherSwitch network module, stacking means connecting two EtherSwitch network modules inside a chassis so that they behave as one switch.
STP—Spanning Tree Protocol. Bridge protocol that uses the spanning-tree algorithm, which enables a learning bridge to dynamically work around loops in a network topology by creating a spanning tree. Bridges exchange Bridge Protocol Data Unit (BPDU) messages with other bridges to detect loops and then remove the loops by shutting down selected bridge interfaces. Refers to both the IEEE 802.1 Spanning-Tree Protocol standard and the earlier Digital Equipment Corporation Spanning-Tree Protocol upon which it is based. The IEEE version supports bridge domains and allows the bridge to construct a loop-free topology across an extended LAN. The IEEE version generally is preferred over the Digital version.
supplicant—Entity requesting access to the network via the authenticator.
SVI—Switch Virtual Interface. Represents a VLAN of switch ports as one interface to the routing or bridging function in a system.
VBR—variable bit rate. QoS class defined by the ATM Forum for ATM networks. VBR is subdivided into a real time (RT) class and non-real time (NRT) class. VBR (RT) is used for connections in which there is a fixed timing relationship between samples. VBR (NRT) is used for connections in which there is no fixed timing relationship between samples but that still need a guaranteed QoS.
VLAN—virtual LAN. Group of devices on one or more LANs that are configured (using management software) so that they can communicate as if they were attached to the same wire, when in fact they are on separate LAN segments. Because VLANs are based on logical instead of physical connections, they are extremely flexible.
VoIP—Voice over IP. Ability to carry normal telephony-style voice over an IP-based internet with POTS-like functionality, reliability, and voice quality. VoIP enables a router to carry voice traffic (such as telephone calls and faxes) over an IP network. In VoIP, the digital signal processor (DSP) segments the voice signal into frames, which then are coupled in groups of two and stored in voice packets. These voice packets are transported using IP in compliance with ITU-T specification H.323.
VoIPoFR—Voice-over-IP over Frame-Relay.
VPN—virtual private network. Enables IP traffic to travel securely over a public TCP/IP network by encrypting all traffic from one network to another. A VPN uses “tunneling” to encrypt all information at the IP level.
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VQP—VLAN Query Protocol.
VTP—VLAN Trunking Protocol.
WAN—wide area network. A communications network that covers a wide geographic area such as state or country. A LAN (local-area network) is within a building or complex, and a MAN (metropolitan-area network) generally covers a city or suburb.
WFQ—weighted fair queuing. In QoS, a flow-based queuing algorithm that schedules low-volume traffic first while letting high-volume traffic share the remaining bandwidth. This is handled by assigning a weight to each flow, where lower weights are the first to be serviced.
WRR—Weighted Round-Robin. Type of round-robin scheduling that prevents low-priority queues from being completely neglected during periods of high-priority traffic. The WRR scheduler transmits some packets from each queue in turn. The number of packets it transmits corresponds to the relative importance of the queue.
Note Refer to Internetworking Terms and Acronyms for terms not included in this glossary.
Part 2: Multilayer Switching
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Multilayer Switching Overview
This chapter provides an overview of Multilayer Switching (MLS).
Note The information in this chapter is a brief summary of the information contained in the Catalyst 5000 Series Multilayer Switching User Guide. The commands and configurations described in this guide apply only to the devices that provide routing services. Commands and configurations for Catalyst 5000 series switches are documented in the Catalyst 5000 Series Multilayer Switching User Guide.
MLS provides high-performance Layer 3 switching for Cisco routers and switches. MLS switches IP data packets between subnets using advanced application-specific integrated circuit (ASIC) switching hardware. Standard routing protocols, such as Open Shortest Path First (OSPF), Enhanced Interior Gateway Routing Protocol (Enhanced IGRP), Routing Information Protocol (RIP), and Intermediate System-to-Intermediate System (IS-IS), are used for route determination.
MLS enables hardware-based Layer 3 switching to offload routers from forwarding unicast IP data packets over shared media networking technologies such as Ethernet. The packet forwarding function is moved onto Layer 3 Cisco series switches whenever a partial or complete switched path exists between two hosts. Packets that do not have a partial or complete switched path to reach their destinations still use routers for forwarding packets.
MLS also provides traffic statistics as part of its switching function. These statistics are used for identifying traffic characteristics for administration, planning, and troubleshooting. MLS uses NetFlow Data Export (NDE) to export the flow statistics.
Procedures for configuring MLS and NDE on routers are provided in the “Configuring IP Multilayer Switching” chapter.
Procedures for configuring MLS and NDE on routers are provided in the following chapters in this publication:
• “Configuring IP Multilayer Switching” chapter
• “Configuring IP Multicast Multilayer Switching” chapter
• “Configuring IPX Multilayer Switching” chapter
This chapter describes MLS. It contains the following sections:
• Terminology
• Introduction to MLS
• Key MLS Features
• MLS Implementation
• Standard and Extended Access Lists
Multilayer Switching OverviewTerminology
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• Introduction to IP Multicast MLS
• Introduction to IPX MLS
• Guidelines for External Routers
• Features That Affect MLS
TerminologyThe following terminology is used in the MLS chapters:
• Multilayer Switching-Switching Engine (MLS-SE)—A NetFlow Feature Card (NFFC)-equipped Catalyst 5000 series switch.
• Multilayer Switching-Route Processor (MLS-RP)—A Cisco router with MLS enabled.
• Multilayer Switching Protocol (MLSP)—The protocol running between the MLS-SE and MLS-RP to enable MLS.
Introduction to MLSLayer 3 protocols, such as IP and Internetwork Packet Exchange (IPX), are connectionless—they deliver each packet independently of each other. However, actual network traffic consists of many end-to-end conversations, or flows, between users or applications.
A flow is a unidirectional sequence of packets between a particular source and destination that share the same protocol and transport-layer information. Communication from a client to a server and from the server to the client is in separate flows. For example, HTTP Web packets from a particular source to a particular destination are in a separate flow from File Transfer Protocol (FTP) file transfer packets between the same pair of hosts.
Flows can be based on only Layer 3 addresses. This feature allows IP traffic from multiple users or applications to a particular destination to be carried on a single flow if only the destination IP address is used to identify a flow.
The NFFC maintains a Layer 3 switching table (MLS cache) for the Layer 3-switched flows. The cache also includes entries for traffic statistics that are updated in tandem with the switching of packets. After the MLS cache is created, packets identified as belonging to an existing flow can be Layer 3-switched based on the cached information. The MLS cache maintains flow information for all active flows. When the Layer 3-switching entry for a flow ages out, the flow statistics can be exported to a flow collector application.
For information on multicast MLS, see the “Introduction to IP Multicast MLS” section in this chapter.
Multilayer Switching OverviewKey MLS Features
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Key MLS FeaturesTable 25 lists the key MLS features.
Table 25 Summary of Key Features
Feature Description
Ease of Use Is autoconfigurable and autonomously sets up its Layer 3 flow cache. Its “plug-and-play” design eliminates the need for you to learn new IP switching technologies.
Transparency Requires no end-system changes and no renumbering of subnets. It works with DHCP1 and requires no new routing protocols.
1. DHCP = Dynamic Host Configuration Protocol
Standards Based Uses IETF2 standard routing protocols such as OSPF and RIP for route determination. You can deploy MLS in a multivendor network.
2. IETF = Internet Engineering Task Force
Investment Protection Provides a simple feature-card upgrade on the Catalyst 5000 series switches. You can use MLS with your existing chassis and modules. MLS also allows you to use either an integrated RSM or an external router for route processing and Cisco IOS services.
Fast Convergence Allows you to respond to route failures and routing topology changes by performing hardware-assisted invalidation of flow entries.
Resilience Provides the benefits of HSRP3 without additional configuration. This feature enables the switches to transparently switch over to the Hot Standby backup router when the primary router goes offline, eliminating a single point of failure in the network.
3. HSRP = Hot Standby Router Protocol
Access Lists Allows you to set up access lists to filter, or to prevent traffic between members of different subnets. MLS enforces multiple security levels on every packet of the flow at wire speed. It allows you to configure and enforce access control rules on the RSM. Because MLS parses the packet up to the transport layer, it enables access lists to be validated. By providing multiple security levels, MLS enables you to set up rules and control traffic based on IP addresses and transport-layer application port numbers.
Accounting and Traffic Management
Allows you to see data flows as they are switched for troubleshooting, traffic management, and accounting purposes. MLS uses NDE to export the flow statistics. Data collection of flow statistics is maintained in hardware with no impact on switching performance. The records for expired and purged flows are grouped and exported to applications such as NetSys for network planning, RMON24 traffic management and monitoring, and accounting applications.
4. RMON2 = Remote Monitoring 2
Network Design Simplification
Enables you to speed up your network while retaining the existing subnet structure. It makes the number of Layer 3 hops irrelevant in campus design, enabling you to cope with increases in any-to-any traffic.
Media Speed Access to Server Farms
You do not need to centralize servers in multiple VLANs to get direct connections. By providing security on a per-flow basis, you can control access to the servers and filter traffic based on subnet numbers and transport-layer application ports without compromising Layer 3 switching performance.
Faster Interworkgroup Connectivity
Addresses the need for higher-performance interworkgroup connectivity by intranet and multimedia applications. By deploying MLS, you gain the benefits of both switching and routing on the same platform.
Multilayer Switching OverviewMLS Implementation
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MLS ImplementationThis section provides a step-by-step description of MLS implementation.
Note The MLS-RPs shown in the figures represent either a RSM or an externally attached Cisco router.
The MLSP informs the Catalyst 5000 series switch of the MLS-RP MAC addresses used on different VLANs and the MLS-RP’s routing and access list changes. Through this protocol, the MLS-RP multicasts its MAC and VLAN information to all MLS-SEs. When the MLS-SE hears the MLSP hello message indicating an MLS initialization, the MLS-SE is programmed with the MLS-RP MAC address and its associated VLAN number (see Figure 42).
Figure 42 MLS Implementation
In Figure 43, Host A and Host B are located on different VLANs. Host A initiates a data transfer to Host B. When Host A sends the first packet to the MLS-RP, the MLS-SE recognizes this packet as a candidate packet for Layer 3 switching because the MLS-SE has learned the MLS-RP’s destination MAC address and VLAN through MLSP. The MLS-SE learns the Layer 3 flow information (such as the destination address, source address, and protocol port numbers), and forwards the first packet to the MLS-RP. A partial MLS entry for this Layer 3 flow is created in the MLS cache.
The MLS-RP receives the packet, looks at its route table to determine how to forward the packet, and applies services such as Access Control Lists (ACLs) and class of service (COS) policy.
The MLS-RP rewrites the MAC header adding a new destination MAC address (Host B’s) and its own MAC address as the source.
MLS-RP multicasts itsMAC addresses andVLAN number to allMLS-SEs…
… all MLS-SEsprogram the NFFCwith the MSLP hellomessage information
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Figure 43 MLS Implementation
The MLS-RP routes the packet to Host B. When the packet appears back on the Catalyst 5000 series switch backplane, the MLS-SE recognizes the source MAC address as that of the MLS-RP, and that the packet’s flow information matches the flow for which it set up a candidate entry. The MLS-SE considers this packet an enabler packet and completes the MLS entry (established by the candidate packet) in the MLS cache (see Figure 44).
Figure 44 MLS Implementation
After the MLS entry has been completed, all Layer 3 packets with the same flow from Host A to Host B are Layer 3 switched directly inside the switch from Host A to Host B, bypassing the router (see Figure 45). After the Layer 3-switched path is established, the packet from Host A is rewritten by the MLS-SE before it is forwarded to Host B. The rewritten information includes the MAC addresses, encapsulations (when applicable), and some Layer 3 information.
The resultant packet format and protocol behavior is identical to that of a packet that is routed by the RSM or external Cisco router.
Note MLS is unidirectional. For Host B to communicate with Host A, another Layer 3-switched path needs to be created from Host B to Host A.
MLS-RP
(MLS-SE)
1200
1
Host A Host B
Because the Catalyst switch has learnedthe MAC and VLAN information of the MLS-RP,the switch starts the MLS process for the Layer 3flow contained in this packet, the candidate packet
Candidate packet
MLS-RP
(MLS-SE)
1200
2
Host A Host B
The MLS-RP routes this packet to Host B. Because the MLS-SE has learned both this MLS-RP and the Layer 3 flow in this packet, it completes the MLS entry in the MLS cache. The first routed packet is called the enabler packet
Enabler packet
Multilayer Switching OverviewStandard and Extended Access Lists
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Figure 45 MLS Implementation
See the Catalyst 5000 Series Multilayer Switching User Guide for additional network implementation examples that include network topologies that do not support MLS.
Standard and Extended Access Lists
Note Router interfaces with input access lists cannot participate in MLS. However, any input access list can be translated to an output access list to provide the same effect on the interface. For complete details on how input and output access lists affect MLS, see the chapter “Configuring Multilayer Switching.”
MLS allows you to enforce access lists on every packet of the flow without compromising MLS performance. When you enable MLS, standard and extended access lists are handled at wire speed by the MLS-SE. Access lists configured on the MLS-RP take effect automatically on the MLS-SE.
Additionally, route topology changes and the addition of access lists are reflected in the switching path of MLS.
Consider the case where an access list is configured on the MLS-RP to deny access from Station A to Station B. When Station A wants to communicate with Station B, it sends the first packet to the MLS-RP. The MLS-RP receives this packet and checks to learn if this packet flow is permitted. If an ACL is configured for this flow, the packet is discarded. Because the first packet for this flow does not return from the MLS-RP, an MLS cache entry is not established by the MLS-SE.
In another case, access lists are introduced on the MLS-RP while the flow is already being Layer 3 switched within the MLS-SE. The MLS-SE immediately enforces security for the affected flow by purging it.
Similarly, when the MLS-RP detects a routing topology change, the appropriate MLS cache entries are deleted in the MLS-SE. The techniques for handling route and access list changes apply to both the RSM and directly attached external routers.
MLS-RP
(MLS-SE)
1200
3
Host A Host B
Layer 3-switched packets
With the MLS entry from Host A to B established, the Layer 3 traffic for this flow is switched directly insidethe Catalyst switch without going to the router
Multilayer Switching OverviewIntroduction to IP Multicast MLS
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Restrictions on Using IP Router Commands with MLS EnabledThe following Cisco IOS commands affect MLS on your router:
• clear ip-route—Clears all MLS cache entries for all Catalyst 5000 series switches performing Layer 3 switching for this MLS-RP.
• ip routing—The no form purges all MLS cache entries and disables MLS on this MLS-RP.
• ip security (all forms of this command)—Disables MLS on the interface.
• ip tcp compression-connections—Disables MLS on the interface.
• ip tcp header-compression—Disables MLS on the interface.
General GuidelinesThe following is a list of general guidelines to enabling MLS:
• When you enable MLS, the RSM or externally attached router continues to handle all non-IP protocols while offloading the switching of IP packets to the MLS-SE.
• Do not confuse MLS with the NetFlow switching supported by Cisco routers. MLS uses both the RSM or directly attached external router and the MLS-SE. With MLS, you are not required to use NetFlow switching on the RSM or directly attached external router; any switching path on the RSM or directly attached external router will work (process, fast, and so on).
Introduction to IP Multicast MLSThe IP multicast MLS feature provides high-performance, hardware-based, Layer 3 switching of IP multicast traffic for routers connected to LAN switches.
An IP multicast flow is a unidirectional sequence of packets between a multicast source and the members of a destination multicast group. Flows are based on the IP address of the source device and the destination IP multicast group address.
IP multicast MLS switches IP multicast data packet flows between IP subnets using advanced, ASIC switching hardware, thereby off loading processor-intensive, multicast packet routing from network routers.
The packet forwarding function is moved onto the connected Layer 3 switch whenever a supported path exists between a source and members of a multicast group. Packets that do not have a supported path to reach their destinations are still forwarded in software by routers. Protocol Independent Multicast (PIM) is used for route determination.
IP Multicast MLS Network TopologyIP multicast MLS requires specific network topologies to function correctly. In each of these topologies, the source traffic is received on the switch, traverses a trunk link to the router, and returns to the switch over the same trunk link to reach the destination group members. The basic topology consists of a switch and an internal or external router connected through an ISL or 802.1Q trunk link.
Figure 46 shows this basic configuration before and after IP multicast MLS is deployed (assuming a completely switched flow). The topology consists of a switch, a directly connected external router, and multiple IP subnetworks (VLANs).
Multilayer Switching OverviewIntroduction to IP Multicast MLS
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The network in the upper diagram in Figure 46 does not have the IP multicast MLS feature enabled. Note the arrows from the router to each multicast group in each VLAN. In this case, the router must replicate the multicast data packets to the multiple VLANs. The router can be easily overwhelmed with forwarding and replicated multicast traffic if the input rate or the number of outgoing interfaces increases.
As shown in the lower diagram in Figure 46, this potential problem is prevented by having the switch hardware forward the multicast data traffic. (Multicast control packets are still moving between the router and switch.)
Figure 46 Basic IP Multicast MLS Network Topology
Benefits of multicast MLS are as follows:
• Improves throughput—The improves throughput feature improves the router’s multicast Layer 3 forwarding and replication throughput.
• Reduces load on router—If the router must replicate many multicast packets to many VLANs, it can be overwhelmed as the input rate and number of outgoing interfaces increase. Configuring the switch to replicate and forward the multicast flow reduces the demand on the router.
Router
Trunk linkVLANs 100, 200, 300
Trunk linkVLANs 100, 200, 300
G1member
G1member
G1member
G1 source
VLAN 300
VLAN 200
VLAN 100
Router(MMLS-RP)
G1member
G1member
G1member
G1source
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VLAN 200
VLAN 100
Switch
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Before IP multicast MLS
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• Provides IP multicast scalability—If you need high throughput of multicast traffic, install a Catalyst 5000 series switch and configure the Provides IP Multicast Scalability feature. By reducing the load on your router, the router can accommodate more multicast flows.
• Provides meaningful flow statistics—IP multicast MLS provides flow statistics that can be used to administer, plan, and troubleshoot networks.
IP Multicast MLS ComponentsAn IP multicast MLS network topology has two components:
• Multicast MLS-Switching Engine (MMLS-SE)—For example, a Catalyst 5000 series switch with hardware that supports IP multicast MLS. The MMLS-SE provides Layer 3 LAN-switching services.
• Multicast MLS-Route Processor (MMLS-RP)—Routing platform running Cisco IOS software that supports IP multicast MLS. The MMLS-RP interacts with the IP multicast routing software and updates the MLS cache in the MMLS-SE. When you enable IP multicast MLS, the MMLS-RP continues to handle all non-IP-multicast traffic while off loading IP multicast traffic forwarding to the MMLS-SE.
Layer 2 Multicast Forwarding TableThe MMLS-SE uses the Layer 2 multicast forwarding table to determine on which ports Layer 2 multicast traffic should be forwarded (if any). The Layer 2 multicast forwarding table is populated by enabling CGMP, IGMP snooping, or GMRP on the switch. These entries map the destination multicast MAC address to outgoing switch ports for a given VLAN.
Layer 3 Multicast MLS CacheThe MMLS-SE maintains the Layer 3 MLS cache to identify individual IP multicast flows. Each entry is of the form {source IP, destination group IP, source VLAN}. The maximum MLS cache size is 128K and is shared by all MLS processes on the switch (such as IP unicast MLS and IPX MLS). However, if the total of cache entries exceeds 32K, there is increased probability that a flow will not be switched by the MMLS-SE and will get forwarded to the router.
The MMLS-SE populates the MLS cache using information learned from the routers participating in IP multicast MLS. The router and switch exchange information using the multicast MLSP.
Whenever the router receives traffic for a new flow, it updates its multicast routing table and forwards the new information to the MMLS-SE using multicast MLSP. In addition, if an entry in the multicast routing table is aged out, the router deletes the entry and forwards the updated information to the MMLS-SE.
The MLS cache contains flow information for all active multilayer switched flows. After the MLS cache is populated, multicast packets identified as belonging to an existing flow can be Layer 3 switched based on the cache entry for that flow. For each cache entry, the MMLS-SE maintains a list of outgoing interfaces for the destination IP multicast group. The MMLS-SE uses this list to determine on which VLANs traffic to a given multicast flow should be replicated.
Multilayer Switching OverviewIntroduction to IP Multicast MLS
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IP Multicast MLS Flow MaskIP multicast MLS supports a single flow mask, source destination vlan. The MMLS-SE maintains one multicast MLS cache entry for each {source IP, destination group IP, source VLAN}. The multicast source destination vlan flow mask differs from the IP unicast MLS source destination ip flow mask in that, for IP multicast MLS, the source VLAN is included as part of the entry. The source VLAN is the multicast Reverse Path Forwarding (RPF) interface for the multicast flow.
Layer 3-Switched Multicast Packet RewriteWhen a multicast packet is Layer 3-switched from a multicast source to a destination multicast group, the MMLS-SE performs a packet rewrite based on information learned from the MMLS-RP and stored in the multicast MLS cache.
For example, if Server A sends a multicast packet addressed to IP multicast group G1 and members of group G1 are on VLANs other than the source VLAN, the MMLS-SE must perform a packet rewrite when it replicates the traffic to the other VLANs (the switch also bridges the packet in the source VLAN).
When the MMLS-SE receives the multicast packet, it is formatted similarly to the sample shown in Table 26.
The MMLS-SE rewrites the packet as follows:
• Changes the source MAC address in the Layer 2 frame header from the MAC address of the server to the MAC address of the MMLS-RP (this MAC address is stored in the multicast MLS cache entry for the flow)
• Decrements the IP header Time to Live (TTL) by one and recalculates the IP header checksum
The result is a rewritten IP multicast packet that appears to have been routed by the router. The MMLS-SE replicates the rewritten packet onto the appropriate destination VLANs, where it is forwarded to members of IP multicast group G1.
After the MMLS-SE performs the packet rewrite, the packet is formatted as shown in Table 27:
Table 26 Layer 3-Switched Multicast Packet Header
Frame Header IP Header Payload
Destination Source Destination Source TTL Checksum Data Checksum
Group G1 MAC
Server A MAC
Group G1 IP Server A IP n calculation1
Table 27 Layer 3-Switched Multicast Packet Header with Rewrite
Frame Header IP Header Payload
Destination Source Destination Source TTL Checksum Data Checksum
Group G1 MAC
MMLS-RP MAC
Group G1 IP Server A IP n – 1 calculation2
Multilayer Switching OverviewIntroduction to IPX MLS
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Partially and Completely Switched FlowsWhen at least one outgoing router interface for a given flow is multilayer switched, and at least one outgoing interface is not multilayer switched, that flow is considered partially switched. When a partially switched flow is created, all multicast traffic belonging to that flow still reaches the router and is software forwarded on those outgoing interfaces that are not multilayer switched.
A flow might be partially switched instead of completely switched in the following situations:
• Some multicast group destinations are located across the router (not all multicast traffic is received and sent on subinterfaces of the same trunk link).
• The router is configured as a member of the IP multicast group (using the ip igmp join-group interface command) on the RPF interface of the multicast source.
• The router is the first-hop router to the source in PIM sparse mode (in this case, the router must send PIM-register messages to the rendezvous point [RP]).
• Multicast TTL threshold or multicast boundary is configured on an outgoing interface for the flow.
• Multicast helper is configured on the RPF interface for the flow and multicast to broadcast translation is required.
• Access list restrictions are configured on an outgoing interface (see the “Access List Restrictions and Guidelines” section in the “Configuring Multicast Multilayer Switching” chapter).
• Integrated routing and bridging (IRB) is configured on the ingress interface.
• An output rate limit is configured on an outgoing interface.
• Multicast tag switching is configured on an outgoing interface.
When all the outgoing router interfaces for a given flow are multilayer switched, and none of the situations described applies to the flow, that flow is considered completely switched. When a completely switched flow is created, the MMLS-SE prevents multicast traffic bridged on the source VLAN for that flow from reaching the MMLS-RP interface in that VLAN, reducing the load on the router.
One consequence of a completely switched flow is that the router cannot record multicast statistics for that flow. Therefore, the MMLS-SE periodically sends multicast packet and byte count statistics for all completely switched flows to the router using multicast MLSP. The router updates the corresponding multicast routing table entry and resets the expiration timer for that multicast route.
Introduction to IPX MLSThe IPX MLS feature provides high-performance, hardware-based, Layer 3 switching for LAN switches. IPX data packet flows are switched between networks, off loading processor-intensive packet routing from network routers.
Whenever a partial or complete switched path exists between two hosts, packet forwarding occurs on Layer 3 switches. Packets without such a partial or complete switched path are still forwarded by routers to their destinations. Standard routing protocols such as RIP, Enhanced IGRP, and NetWare Link Services Protocol (NLSP) are used for route determination.
IPX MLS also allows you to debug and trace flows in your network. Use MLS explorer packets to identify which switch is handling a particular flow. These packets aid you in path detection and troubleshooting.
Multilayer Switching OverviewIntroduction to IPX MLS
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IPX MLS ComponentsAn IPX MLS network topology has the following components:
• MLS-SE—For example, a Catalyst 5000 series switch with the Netflow Feature Card (NFFC II). The MLS-SE provides Layer 3 LAN-switching services.
• MLS-RP—For example, a Catalyst 5000 series RSM or an externally connected Cisco 4500, 4700, 7200, or 7500 series router with software that supports MLS. The MLS-RP provides Cisco IOS-based multiprotocol routing, network services, and central configuration and control for the switches.
• MLSP—The protocol running between the MLS-SE and MLS-RP that enables MLS.
IPX MLS FlowsLayer 3 protocols such as IP and IPX are connectionless—they deliver every packet independently of every other packet. However, actual network traffic consists of many end-to-end conversations, or flows, between users or applications.
A flow is a unidirectional packet sequence between a particular source and destination that share identical protocol and network-layer information. Communication flows from a client to a server and from the server to the client are distinct.
Flows are based only on Layer 3 addresses. If a destination IPX address identifies a flow, then IPX traffic from multiple users or applications to a particular destination can be carried on a single flow.
Layer 3-switched flows appear in the MLS cache, a special Layer 3 switching table is maintained by the NFFC II. The cache contains traffic statistics entries that are updated in tandem with packet switching. After the MLS cache is created, packets identified as belonging to an existing flow can be Layer 3 switched. The MLS cache maintains flow information for all active flows.
MLS CacheThe MLS-SE maintains a cache for IPX MLS flows and maintains statistics for each flow. An IPX MLS cache entry is created for the initial packet of each flow. Upon receipt of a packet that does not match any flow in the MLS cache, a new IPX MLS entry is created.
The state and identity of the flow are maintained while packet traffic is active; when traffic for a flow ceases, the entry ages out. You can configure the aging time for IPX MLS entries kept in the MLS cache. If an entry is not used for the specified period of time, the entry ages out and statistics for that flow can be exported to a flow collector application.
The maximum MLS cache size is 128,000 entries. However, an MLS cache larger than 32,000 entries increases the probability that a flow will not be switched by the MLS-SE and will get forwarded to the router.
Note The number of active flows that can be switched using the MLS cache depends on the type of access lists configured on MLS router interfaces (which determines the flow mask). See the “Flow Mask Modes” section later in this document.
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Flow Mask ModesTwo flow mask modes—destination mode and destination-source mode—determine how IPX MLS entries are created for the MLS-SE.
You determine the mode when you configure IPX access lists on the MLS-RP router interfaces. Each MLS-RP sends MLSP messages about its flow mask to the MLS-SE, which performs Layer 3 switching. The MLS-SE supports only the most specific flow mask for its MLS-RPs. If it detects more than one mask, it changes to the most specific mask and purges the entire MLS cache. When an MLS-SE exports cached entries, it creates flow records from the most current flow mask mode. Depending on the current mode, some fields in the flow record might not have values. Unsupported fields are filled with a zero (0).
The two modes are described, as follows:
• Destination mode—The least-specific flow mask mode. The MLS-SE maintains one IPX MLS entry for each destination IPX address (network and node). All flows to a given destination IPX address use this IPX MLS entry. Use this mode if no access lists have been configured according to source IPX address on any of the IPX MLS router interfaces. In this mode the destination IPX address of the switched flows is displayed, along with the rewrite information: rewritten destination MAC, rewritten VLAN, and egress port.
• Destination-source mode—The MLS-SE maintains one MLS entry for each destination (network and node) and source (network only) IPX address pair. All flows between a given source and destination use this MLS entry regardless of the IPX sockets. Use this mode if an access list exists on any MLS-RP IPX interfaces that filter on source network.
Note The flow mask mode determines the display of the show mls rp ipx EXEC command. Refer to the Cisco IOS Switching Services Command Reference for details.
Layer 3-Switched Packet RewriteWhen a packet is Layer 3 switched from a source host to a destination host, the switch (MLS-SE) performs a packet rewrite based on information it learned from the router (MLS-RP) and then stored in the MLS cache.
If Host A and Host B are on different VLANs and Host A sends a packet to the MLS-RP to be routed to Host B, the MLS-SE recognizes that the packet was sent to the MAC address of the MLS-RP. The MLS-SE then checks the MLS cache and finds the entry matching the flow in question.
When the MLS-SE receives the packet, it is formatted as shown in Table 28:
Table 28 Layer 3-Switched Packet Header Sent to the MLS-RP
Frame Header Encap IPX Header Payload
Destination Source Length Checksum/ IPX Length/ Transport Control1
1. Transport Control counts the number of times this packet has been routed. If this number is greater than the maximum (the default is 16), then the packet is dropped.
Packet Type
Destination Net/Node/ Socket
Source Net/Node/ Socket
Data PAD/FCS
MLS-RP MAC
Host A MAC
Host B IPX Host A IPX
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The MLS-SE rewrites the Layer 2 frame header, changing the destination MAC address to that of Host B and the source MAC address to that of the MLS-RP (these MAC addresses are stored in the IPX MLS cache entry for this flow). The Layer 3 IPX addresses remain the same. The MLS-SE rewrites the switched Layer 3 packets so that they appear to have been routed by a router.
The MLS-SE forwards the rewritten packet to Host B’s VLAN (the destination VLAN is saved in the IPX MLS cache entry) and Host B receives the packet.
After the MLS-SE performs the packet rewrite, the packet is formatted as shown in Table 29:
IPX MLS Operation Figure 47 shows a simple IPX MLS network topology:
• Host A is on the Sales VLAN (IPX address 01.Aa).
• Host B is on the Marketing VLAN (IPX address 03.Bb).
• Host C is on the Engineering VLAN (IPX address 02.Cc).
When Host A initiates a file transfer to Host B, an IPX MLS entry for this flow is created (see the first item in Figure 47’s table). When the MLS-RP forwards the first packet from Host A through the switch to Host B, the MLS-SE stores the MAC addresses of the MLS-RP and Host B in the IPX MLS entry. The MLS-SE uses this information to rewrite subsequent packets from Host A to Host B.
Similarly, a separate IPX MLS entry is created in the MLS cache for the traffic from Host A to Host C, and for the traffic from Host C to Host A. The destination VLAN is stored as part of each IPX MLS entry so that the correct VLAN identifier is used for encapsulating traffic on trunk links.
Table 29 Layer 3-Switched Packet with Rewrite from the MLS-RP
Frame Header Encap IPX Header Payload
Destination Source Length Checksum/ IPX Length/ Transport Control
Packet Type
Destination Net/Node/ Socket
Source Net/Node/ Socket
Data PAD/FCS
Host B MAC MLS-RP MAC
Host B IPX Host A IPX
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Figure 47 IPX MLS Example Topology
Standard Access Lists
Note Router interfaces with input access lists or outbound access lists unsupported by MLS cannot participate in IPX MLS. However, you can translate any input access list to an output access list to provide the same effect on the interface.
IPX MLS enforces access lists on every packet of the flow, without compromising IPX MLS performance. The MLS-SE handles permit traffic supported by MLS at wire speed.
Note Access list deny traffic is always handled by the MLS-RP, not the MLS-SE.
The MLS switching path automatically reflects route topology changes and the addition or modification of access lists on the MLS-SE. The techniques for handling route and access list changes apply to both the RSM and directly attached external routers.
For example, for Stations A and B to communicate, Station A sends the first packet to the MLS-RP. If the MLS-RP is configured with an access list to deny access from Station A to Station B, the MLS-RP receives the packet, checks its access list permissions to learn if the packet flow is permitted, and then discards the packet. Because the MLS-SE does not receive the returned first packet for this flow from the MLS-RP, the MLS-SE does not create an MLS cache entry.
Source IPX Address
01.Aa
01.Aa
02.Cc
01.Aa:02.CcData
03.Bb
02.Cc
01.Aa
Dd:Bb
Dd:Cc
Dd:Aa
Marketing
Engineering
Sales
DestinationIPX Address
Rewrite Src/DstMAC Address
DestinationVLAN
RSM
Net 1/Sales
01
MAC = Aa
MAC = Dd
MAC = Bb
MAC = Cc
Net 3/Marketing
03
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Multilayer Switching OverviewGuidelines for External Routers
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In contrast, if the MLS-SE is already Layer 3 switching a flow and the access list is created on the MLS-RP, MLSP notifies the MLS-SE, and the MLS-SE immediately purges the affected flow from the MLS cache. New flows are created based on the restrictions imposed by the access list.
Similarly, when the MLS-RP detects a routing topology change, the MLS-SE deletes the appropriate MLS cache entries, and new flows are created based on the new topology.
Guidelines for External RoutersWhen using an external router, follow these guidelines:
• We recommend one directly attached external router per Catalyst 5000 series switch to ensure that the MLS-SE caches the appropriate flow information from both sides of the routed flow.
• You can use Cisco high-end routers (Cisco 7500, 7200, 4500, and 4700 series) for MLS when they are externally attached to the Catalyst 5000 series switch. You can make the attachment with multiple Ethernets (one per subnet), by using Fast Ethernet with the ISL, or with Fast Etherchannel.
• You can connect end hosts through any media (Ethernet, Fast Ethernet, ATM, and FDDI) but the connection between the external router and the Catalyst 5000 series switch must be through standard 10/100 Ethernet interfaces, ISL links, or Fast Etherchannel.
Features That Affect MLSThis section describes how certain features affect MLS.
Access ListsThe following sections describe how access lists affect MLS.
Input Access Lists
Router interfaces with input access lists cannot participate in MLS. If you configure an input access list on an interface, all packets for a flow that are destined for that interface go through the router (even if the flow is allowed by the router it is not Layer 3 switched). Existing flows for that interface get purged and no new flows are cached.
Note Any input access list can be translated to an output access list to provide the same effect on the interface.
Output Access Lists
If an output access list is applied to an interface, the MLS cache entries for that interface are purged. Entries associated with other interfaces are not affected; they follow their normal aging or purging procedures.
Applying an output access list to an interface, when the access list is configured using the log, precedence, tos, or establish keywords, prevents the interface from participating in MLS.
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Access List Impact on Flow Masks
Access lists impact the flow mask advertised by an MLS-RP. When no access list on any MLS-RP interface, the flow mask mode is destination-ip (the least specific). When there is a standard access list is on any of the MLS-RP interfaces, the mode is source-destination-ip. When there is an extended access list is on any of the MLS-RP interfaces, the mode is ip-flow (the most specific).
Reflexive Access Lists
Router interfaces with reflexive access lists cannot participate in Layer 3 switching.
IP Accounting Enabling IP accounting on an MLS-enabled interface disables the IP accounting functions on that interface.
Note To collect statistics for the Layer 3-switched traffic, enable NDE.
Data EncryptionMLS is disabled on an interface when the data encryption feature is configured on the interface.
Policy Route MapsMLS is disabled on an interface when a policy route map is configured on the interface.
TCP InterceptWith MLS interfaces enabled, the TCP intercept feature (enabled in global configuration mode) might not work properly. When you enable the TCP intercept feature, the following message is displayed:
Command accepted, interfaces with mls might cause inconsistent behavior.
Network Address TranslationMLS is disabled on an interface when Network Address Translation (NAT) is configured on the interface.
Committed Access RateMLS is disabled on an interface when committed access rate (CAR) is configured on the interface.
Multilayer Switching OverviewFeatures That Affect MLS
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Maximum Transmission UnitThe maximum transmission unit (MTU) for an MLS interface must be the default Ethernet MTU, 1500 bytes.
To change the MTU on an MLS-enabled interface, you must first disable MLS on the interface (enter no mls rp ip global configuration command in the interface). If you attempt to change the MTU with MLS enabled, the following message is displayed:
Need to turn off the mls router for this interface first.
If you attempt to enable MLS on an interface that has an MTU value other than the default value, the following message is displayed:
mls only supports interfaces with default mtu size
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Configuring IP Multilayer Switching
This chapter describes how to configure your network to perform IP Multilayer Switching (MLS). This chapter contains these sections:
• Configuring and Monitoring MLS
• Configuring NetFlow Data Export
• Multilayer Switching Configuration Examples
For a complete description of the commands in this chapter, refer to the the Cisco IOS Switching Services Command Reference. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
To identify the hardware platform or software image information associated with a feature, use the Feature Navigator on Cisco.com to search for information about the feature or refer to the software release notes for a specific release. For more information, see the section “Finding Additional Feature Support Information” section on page xxxix in the chapter “Using Cisco IOS Software for Release 12.4”
Note The information in this chapter is a brief summary of the information contained in the Catalyst 5000 Series Multilayer Switching User Guide. The commands and configurations described in this guide apply only to the devices that provide routing services. Commands and configurations for Catalyst 5000 series switches are documented in the Catalyst 5000 Series Multilayer Switching User Guide. For configuration information for the Catalyst 6000 series switch, see Configuring and Troubleshooting IP MLS on Catalyst 6000 with an MSFC or the “Configuring IP Multilayer Switching” chapter in the Catalyst 6500 Series MSFC (12.x) & PFC Configuration Guide.
Configuring and Monitoring MLS To configure your Cisco router for MLS, perform the tasks described in the following sections. The first section contains a required task; the remaining tasks are optional. To ensure a successful MLS configuration, you must also configure the Catalyst switches in your network. For a full description for the Catalyst 5000 series, see the Catalyst 5000 Series Multilayer Switching User Guide. For a full description for the Catalyst 6000 series, see the “Configuring IP Multilayer Switching” chapter in the Catalyst 6500 Series MSFC (12.x) & PFC Configuration Guide. Only configuration tasks and commands for routers are described in this chapter.
• Configuring MLS on a Router (Required)
• Monitoring MLS (Optional)
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• Monitoring MLS for an Interface (Optional)
• Monitoring MLS Interfaces for VTP Domains (Optional)
Configuring MLS on a RouterTo configure MLS on your router, use the following commands beginning in global configuration mode. Depending upon your configuration, you might not have to perform all the steps in the procedure.
Note The interface-specific commands in this section apply only to Ethernet, Fast Ethernet, VLAN, and Fast Etherchannel interfaces on the Catalyst RSM/Versatile Interface Processor 2 (VIP2) or directly attached external router.
To globally disable MLS on the router, use the following command in global configuration mode:
Command Purpose
Step 1 Router(config)# mls rp ip Globally enables MLSP. MLSP is the protocol that runs between the MLS-SE and the MLS-RP.
Step 2 Router(config)# interface type number Selects a router interface.
Step 3 Router(config-if)# mls rp vtp-domain [domain-name]
Selects the router interface to be Layer 3 switched and then adds that interface to the same VLAN Trunking Protocol (VTP) domain as the switch. This interface is referred to as the MLS interface. This command is required only if the Catalyst switch is in a VTP domain.
Step 4 Router(config-if)# mls rp vlan-id [vlan-id-num]
Assigns a VLAN ID to the MLS interface. MLS requires that each interface has a VLAN ID. This step is not required for RSM VLAN interfaces or ISL-encapsulated interfaces.
Step 5 Router(config-if)# mls rp ip Enables each MLS interface.
Step 6 Router(config-if)# mls rp management-interface
Selects one MLS interface as a management interface. MLSP packets are sent and received through this interface. This can be any MLS interface connected to the switch.
Repeat steps 2 through 5 for each interface that will support MLS.
Command PurposeRouter(config)# no mls rp ip Disables MLS on the router.
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Monitoring MLSTo display MLS details including specifics for MLSP, use the following commands in EXEC mode, as needed:
• MLS status (enabled or disabled) for switch interfaces and subinterfaces
• Flow mask used by this MLS-enabled switch when creating Layer 3-switching entries for the router
• Current settings of the keepalive timer, retry timer, and retry count
• MLSP-ID used in MLSP messages
• List of interfaces in all VTP domains that are enabled for MLS
After entering this command, you see this display:
router# show mls rp
multilayer switching is globally enabledmls id is 00e0.fefc.6000mls ip address 10.20.26.64mls flow mask is ip-flow vlan domain name: WBU current flow mask: ip-flow current sequence number: 80709115 current/maximum retry count: 0/10 current domain state: no-change current/next global purge: false/false current/next purge count: 0/0 domain uptime: 13:03:19 keepalive timer expires in 9 seconds retry timer not running change timer not running fcp subblock count = 7 1 management interface(s) currently defined: vlan 1 on Vlan1 7 mac-vlan(s) configured for multi-layer switching: mac 00e0.fefc.6000 vlan id(s) 1 10 91 92 93 95 100 router currently aware of following 1 switch(es): switch id 0010.1192.b5ff
Command PurposeRouter# show mls rp Displays MLS details for all interfaces.
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Monitoring MLS for an InterfaceTo show MLS information for a specific interface, use the following command in EXEC mode:
After entering this command, you see this display:
router# show mls rp int vlan 10
mls active on Vlan10, domain WBUrouter#
Monitoring MLS Interfaces for VTP DomainsTo show MLS information for a specific VTP domain use the following command in EXEC mode:
After entering this command, you see this display:
router# show mls rp vtp-domain WBU
vlan domain name: WBU current flow mask: ip-flow current sequence number: 80709115 current/maximum retry count: 0/10 current domain state: no-change current/next global purge: false/false current/next purge count: 0/0 domain uptime: 13:07:36 keepalive timer expires in 8 seconds retry timer not running change timer not running fcp subblock count = 7 1 management interface(s) currently defined: vlan 1 on Vlan1 7 mac-vlan(s) configured for multi-layer switching: mac 00e0.fefc.6000 vlan id(s) 1 10 91 92 93 95 100 router currently aware of following 1 switch(es): switch id 0010.1192.b5ff
Command Purpose
Router# show mls rp [interface] Displays MLS details for a specific interface.
Command Purpose
Router# show mls rp vtp-domain [domain-name] Displays MLS interfaces for a specific VTP domain.
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Configuring NetFlow Data Export
Note You need to enable NDE only if you will export MLS cache entries to a data collection application.
Perform the task in this section to configure your Cisco router for NDE. To ensure a successful NDE configuration, you must also configure the Catalyst switch. For a full description, see the Catalyst 5000 Series Multilayer Switching User Guide.
Specifying an NDE Address on the RouterTo specify an NDE address on the router, use the following command in global configuration mode:
Multilayer Switching Configuration ExamplesIn these examples, VLAN interfaces 1 and 3 are in VTP domain named Engineering. The management interface is configured on the VLAN 1 interface. Only information relevant to MLS is shown in the following configurations:
• Router Configuration Without Access Lists Example
• Router Configuration with a Standard Access List Example
• Router Configuration with an Extended Access List Example
Router Configuration Without Access Lists ExampleThis sample configuration shows a router configured without access lists on any of the VLAN interfaces. The flow mask is configured to be destination-ip.
router# more system:running-config
Building configuration... Current configuration:...mls rp ip
interface Vlan1 ip address 172.20.26.56 255.255.255.0mls rp vtp-domain Engineering
mls rp management-interface mls rp ip
Command PurposeRouter(config)# mls rp nde-address ip-address Specifies an NDE IP address for the router doing the Layer 3
switching. The router and the Catalyst 5000 series switch use the NDE IP address when sending MLS statistics to a data collection application.
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interface Vlan2 ip address 172.16.2.73 255.255.255.0
interface Vlan3 ip address 172.16.3.73 255.255.255.0mls rp vtp-domain Engineering
mls rp ip ..end
router#router# show mls rp
multilayer switching is globally enabledmls id is 0006.7c71.8600mls ip address 172.20.26.56mls flow mask is destination-ip
number of domains configured for mls 1vlan domain name: Engineering current flow mask: destination-ip current sequence number: 82078006 current/maximum retry count: 0/10 current domain state: no-change current/next global purge: false/false current/next purge count: 0/0 domain uptime: 02:54:21 keepalive timer expires in 11 seconds retry timer not running change timer not running 1 management interface(s) currently defined: vlan 1 on Vlan1 2 mac-vlan(s) configured for multi-layer switching: mac 0006.7c71.8600 vlan id(s) 1 3 router currently aware of following 1 switch(es): switch id 00e0.fe4a.aeff
Router Configuration with a Standard Access List ExampleThis configuration is the same as the previous example but with a standard access list configured on the VLAN 3 interface. The flow mask changes to source-destination-ip.
.interface Vlan3 ip address 172.16.3.73 255.255.255.0 ip access-group 2 outmls rp vtp-domain Engineering
mls rp ip.
router# show mls rp
multilayer switching is globally enabledmls id is 0006.7c71.8600mls ip address 172.20.26.56
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mls flow mask is source-destination-ip number of domains configured for mls 1vlan domain name: Engineering current flow mask: source-destination-ip current sequence number: 82078007 current/maximum retry count: 0/10 current domain state: no-change current/next global purge: false/false current/next purge count: 0/0 domain uptime: 02:57:31 keepalive timer expires in 4 seconds retry timer not running change timer not running 1 management interface(s) currently defined: vlan 1 on Vlan1 2 mac-vlan(s) configured for multi-layer switching: mac 0006.7c71.8600 vlan id(s) 1 3 router currently aware of following 1 switch(es): switch id 00e0.fe4a.aeff
Router Configuration with an Extended Access List ExampleThis configuration is the same as the previous examples but with an extended access list configured on the VLAN 3 interface. The flow mask changes to ip-flow.
.interface Vlan3 ip address 172.16.3.73 255.255.255.0 ip access-group 101 outmls rp vtp-domain Engineering
mls rp ip.
router# show mls rp
multilayer switching is globally enabledmls id is 0006.7c71.8600mls ip address 172.20.26.56mls flow mask is ip-flow number of domains configured for mls 1vlan domain name: Engineering current flow mask: ip-flow current sequence number: 82078009 current/maximum retry count: 0/10 current domain state: no-change current/next global purge: false/false current/next purge count: 0/0 domain uptime: 03:01:52 keepalive timer expires in 3 seconds retry timer not running change timer not running 1 management interface(s) currently defined:
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vlan 1 on Vlan1 2 mac-vlan(s) configured for multi-layer switching: mac 0006.7c71.8600 vlan id(s) 1 3 router currently aware of following 1 switch(es): switch id 00e0.fe4a.aeff
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Configuring IP Multicast Multilayer Switching
This chapter describes how to configure your network to perform IP multicast Multilayer Switching (MLS). This chapter contains these sections:
• Prerequisites
• Restrictions
• Configuring and Monitoring IP Multicast MLS
• IP Multicast MLS Configuration Examples
For a complete description of the commands in this chapter, refer to the the Cisco IOS Switching Services Command Reference. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
To identify the hardware platform or software image information associated with a feature, use the Feature Navigator on Cisco.com to search for information about the feature or refer to the software release notes for a specific release. For more information, see the section “Finding Additional Feature Support Information” section on page xxxix in the chapter “Using Cisco IOS Software for Release 12.4”.
Note The information in this chapter is a brief summary of the information contained in the Catalyst 5000 Series Multilayer Switching User Guide. The commands and configurations described in this guide apply only to the devices that provide routing services. Commands and configurations for Catalyst 5000 series switches are documented in the Catalyst 5000 Series Multilayer Switching User Guide.
PrerequisitesThe following prerequisites are necessary before MLS can function:
• A VLAN interface must be configured on both the switch and the router. For information on configuring inter-VLAN routing on the RSM or an external router, refer to the Catalyst 5000 Software Configuration Guide.
• IP multicast MLS must be configured on the switch. For procedures on this task, refer to the “Configuring IP Multicast Routing” chapter in the Cisco IOS IP Routing Configuration Guide.
• IP multicast routing and PIM must be enabled on the router. The minimal steps to configure them are described in the “Configuring and Monitoring IP Multicast MLS” section later in this document. For detailed information on configuring IP multicast routing and PIM, refer to the Cisco IOS IP Routing Configuration Guide.
Configuring IP Multicast Multilayer SwitchingRestrictions
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RestrictionsYou must also configure the Catalyst 5000 series switch in order for IP multicast MLS to function on the router.
The restrictions in the following sections apply to IP multicast MLS on the router:
• Router Configuration Restrictions
• External Router Guidelines
• Access List Restrictions and Guidelines
Router Configuration RestrictionsIP multicast MLS does not work on internal or external routers in the following situations:
• If IP multicast MLS is disabled on the RPF interface for the flow (using the no mls rp ip multicast interface configuration command).
• For IP multicast groups that fall into these ranges (where * is in the range from 0 to 255):
– 224.0.0.* through 239.0.0.*
– 224.128.0.* through 239.128.0.*
Note Groups in the 224.0.0.* range are reserved for routing control packets and must be flooded to all forwarding ports of the VLAN. These addresses map to the multicast MAC address range 01-00-5E-00-00-xx, where xx is in the range from 0 to 0xFF.
• For PIM auto-RP multicast groups (IP multicast group addresses 224.0.1.39 and 224.0.1.40).
• For flows that are forwarded on the multicast shared tree (that is, {*, G, *} forwarding) when the interface or group is running PIM sparse mode.
• If the shortest path tree (SPT) bit for the flow is cleared when running PIM sparse mode for the interface or group.
• When an input rate limit is applied on an RPF interface.
• For any RPF interface with access lists applied (for detailed information, see the “Access List Restrictions and Guidelines” section later in this document).
• For any RPF interface with multicast boundary configured.
• For packets that require fragmentation and packets with IP options. However, packets in the flow that are not fragmented or that do not specify IP options are multilayer switched.
• On external routers, for source traffic received at the router on non-ISL or non-802.1Q interfaces.
• For source traffic received on tunnel interfaces (such as MBONE traffic).
• For any RPF interface with multicast tag switching enabled.
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External Router GuidelinesFollow these guidelines when using an external router:
• The connection to the external router must be over a single ISL or 802.1Q trunk link with subinterfaces (using appropriate encapsulation type) configured.
• A single external router can serve as the MMLS-RP for multiple switches, provided each switch connects to the router through a separate ISL or 802.1Q trunk link.
• If the switch connects to a single router through multiple trunk links, IP multicast MLS is supported on one of the links only. You must disable IP multicast MLS on the redundant links using the no mls rp ip multicast interface configuration command.
• You can connect end hosts (source or multicast destination devices) through any media (Ethernet, Fast Ethernet, ATM, and FDDI), but the connection between external routers and the switch must be through Fast Ethernet or Gigabit Ethernet interfaces.
Access List Restrictions and GuidelinesThe following restrictions apply when using access lists on interfaces participating in IP multicast MLS:
• All standard access lists are supported on any interface. The flow is multilayer switched on all interfaces on which the traffic for the flow is allowed by the access list.
• Layer 4 port-based extended IP input access lists are not supported. For interfaces with these access lists applied, no flows are multilayer switched.
• Extended access lists on the RPF interface that specify conditions other than Layer 3 source, Layer 3 destination, and ip protocol are not multilayer switched.
For example, if the following input access list is applied to the RPF interface for a group of flows, no flows will be multilayer switched even though the second entry permits all IP traffic (because the protocol specified in the first entry is not ip):
Router(config)# access-list 101 permit udp any anyRouter(config)# access-list 101 permit ip any any
If the following input access list is applied to the RPF interface for a group of flows, all flows except the {s1, g1} flow are multilayer switched (because the protocol specified in the entry for {s1, g1} is not ip):
Router(config)# access-list 101 permit udp s1 g1Router(config)# access-list 101 permit ip any any
Configuring and Monitoring IP Multicast MLS To configure your Cisco router for IP multicast MLS, perform the tasks described in the following sections. The first two sections contain required tasks; the remaining tasks are optional. To ensure a successful multicast MLS configuration, you must also configure the Catalyst switches in your network. For a full description, refer to the Catalyst 5000 Series Multilayer Switching User Guide.
• Enabling IP Multicast Routing (Required)
• Enabling IP PIM (Required)
• Enabling IP Multicast MLS (Optional, this is a required task if you disabled it.)
• Specifying a Management Interface (Optional)
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For examples of IP multicast MLS configurations, see the “IP Multicast MLS Configuration Examples” section later in this document.
Enabling IP Multicast RoutingYou must enable IP multicast routing globally on the MMLS-RPs before you can enable IP multicast MLS on router interfaces. To enable IP multicast routing on the router, use the following command in router configuration mode:
Note This section describes only how to enable IP multicast routing on the router. For detailed IP multicast configuration information, refer to the “Configuring IP Multicast Routing” chapter in the Cisco IOS IP Routing Configuration Guide.
Enabling IP PIM You must enable PIM on the router interfaces connected to the switch before IP multicast MLS will function on those router interfaces. To do so, use the following commands beginning in interface configuration mode:
Note This section describes only how to enable PIM on router interfaces. For detailed PIM configuration information, refer to the “Configuring IP Multicast Routing” chapter in the Cisco IOS IP Routing Configuration Guide.
Enabling IP Multicast MLSIP multicast MLS is enabled by default when you enable PIM on the interface. Perform this task only if you disabled IP multicast MLS and you want to reenable it. To enable IP multicast MLS on an interface, use the following command in interface configuration mode:
Command PurposeRouter(config)# ip multicast-routing Enables IP multicast routing globally.
Command Purpose
Step 1 Router(config)# interface type number Configures an interface.
Step 2 Router(config-if)# ip pim {dense-mode | sparse-mode | sparse-dense-mode}
Enables PIM on the interface.
Command PurposeRouter(config-if)# mls rp ip multicast Enables IP multicast MLS on an interface.
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Specifying a Management InterfaceWhen you enable IP multicast MLS, the subinterface (or VLAN interface) that has the lowest VLAN ID and is active (in the “up” state) is automatically selected as the management interface. The one-hop protocol Multilayer Switching Protocol (MLSP) is used between a router and a switch to pass messages about hardware-switched flows. MLSP packets are sent and received on the management interface. Typically, the interface in VLAN 1 is chosen (if that interface exists). Only one management interface is allowed on a single trunk link.
In most cases, we recommend that the management interface be determined by default. However, you can optionally specify a different router interface or subinterface as the management interface. We recommend using a subinterface with minimal data traffic so that multicast MLSP packets can be sent and received more quickly.
If the user-configured management interface goes down, the router uses the default interface (the active interface with the lowest VLAN ID) until the user-configured interface comes up again.
To change the default IP multicast MLS management interface, use the following command in interface configuration mode:
Monitoring and Maintaining IP Multicast MLSTo monitor and maintain an IP multicast MLS network, use the following commands in EXEC modes, as needed:
IP Multicast MLS Configuration ExamplesThe following sections contain example IP multicast MLS implementations. These examples include the switch configurations, although switch commands are not documented in this router publication. Refer to the Catalyst 5000 Command Reference for that information.
• Basic IP Multicast MLS Network Examples
• Complex IP Multicast MLS Network Examples
Command Purpose
Router(config-if)# mls rp ip multicast management-interface Configures an interface as the IP multicast MLS management interface.
Command Purpose
Router# show ip mroute [group-name | group-address [source]] Displays hardware switching state for outgoing interfaces.
Router# show ip pim interface [type number] [count] Displays PIM interface information.
Router# show mls rp ip multicast [locate] [group [source] [vlan-id]] | [statistics] | [summary]
Displays Layer 3 switching information.
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Basic IP Multicast MLS Network ExamplesThis example consists of the following sections:
• Network Topology Example
• Operation Before IP Multicast MLS Example
• Operation After IP Multicast MLS Example
• Router Configuration
• Switch Configuration
Network Topology Example
Figure 48 shows a basic IP multicast MLS example network topology.
Figure 48 Example Network: Basic IP Multicast MLS
The network is configured as follows:
• There are three VLANs (IP subnetworks): VLANs 10, 20, and 30.
• The multicast source for group G1 belongs to VLAN 10.
• Hosts A, C, and D have joined IP multicast group G1.
• Port 1/2 on the MMLS-SE is connected to interface fastethernet2/0 on the MMLS-RP.
• The link between the MMLS-SE and the MMLS-RP is configured as an ISL trunk.
• The subinterfaces on the router interface have these IP addresses:
– fastethernet2/0.10: 10.1.10.1 255.255.255.0 (VLAN 10)
– fastethernet2/0.20: 10.1.20.1 255.255.255.0 (VLAN 20)
– fastethernet2/0.30: 10.1.30.1 255.255.255.0 (VLAN 30)
A
D
B C
Trunk linkVLANs 10, 20, 30
Router(MMLS-RP)
VLAN 1010.1.10.0/24
G1 source
G1
G1
G1
VLAN 2010.1.20.0/24
VLAN 3010.1.30.0/24
Switch(MMLS-SE)
1850
1
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Operation Before IP Multicast MLS Example
Without IP multicast MLS, when the G1 source (on VLAN 10) sends traffic destined for IP multicast group G1, the switch forwards the traffic (based on the Layer 2 multicast forwarding table entry generated by the IGMP snooping, CGMP, or GMRP multicast service) to Host A on VLAN 10 and to the router subinterface in VLAN 10.
The router receives the multicast traffic on its incoming subinterface for VLAN 10, checks the multicast routing table, and replicates the traffic to the outgoing subinterfaces for VLANs 20 and 30. The switch receives the traffic on VLANs 20 and 30 and forwards the traffic received on these VLANs to the appropriate switch ports, again based on the contents of the Layer 2 multicast forwarding table.
Operation After IP Multicast MLS Example
After IP multicast MLS is implemented, when the G1 source sends traffic destined for multicast group G1, the MMLS-SE checks its Layer 3 multicast MLS cache and recognizes that the traffic belongs to a multicast MLS flow. The MMLS-SE forwards the traffic to Host A on VLAN 10 based on the multicast forwarding table, but does not forward the traffic to the router subinterface in VLAN 10 (assuming a completely switched flow).
For each multicast MLS cache entry, the switch maintains a list of outgoing interfaces for the destination IP multicast group. The switch replicates the traffic on the appropriate outgoing interfaces (VLANs 20 and 30) and then forwards the traffic on each VLAN to the destination hosts (using the Layer 2 multicast forwarding table). The switch performs a packet rewrite for the replicated traffic so that the packets appear to have been routed by the appropriate router subinterface.
If not all the router subinterfaces are eligible to participate in IP multicast MLS, the switch must forward the multicast traffic to the router subinterface in the source VLAN (in this case, VLAN 10). In this situation, on those subinterfaces that are ineligible, the router performs multicast forwarding and replication in software, in the usual manner. On those subinterfaces that are eligible, the switch performs multilayer switching.
Note On the MMLS-RP, the IP multicast MLS management interface is user-configured to the VLAN 30 subinterface. If this interface goes down, the system will revert to the default management interface (in this case, the VLAN 10 subinterface).
Router Configuration
The following is an example configuration of IP multicast MLS on the router:
ip multicast-routinginterface fastethernet2/0.10encapsulation isl 10ip address 10.1.10.1 255.255.255.0ip pim dense-mode
interface fastethernet2/0.20encapsulation isl 20ip address 10.1.20.1 255.255.255.0ip pim dense-mode
interface fastethernet2/0.30encapsulation isl 30ip address 10.1.30.1 255.255.255.0 ip pim dense-modemls rp ip multicast management-interface
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You will receive the following message informing you that you changed the management interface:
Warning: MLS Multicast management interface is now Fa2/0.30
Switch Configuration
The following example shows how to configure the switch (MMLS-SE):
Console> (enable) set trunk 1/2 on islPort(s) 1/2 trunk mode set to on.Port(s) 1/2 trunk type set to isl.Console> (enable) set igmp enableIGMP feature for IP multicast enabledConsole> (enable) set mls multicast enableMultilayer Switching for Multicast is enabled for this device.Console> (enable) set mls multicast include 10.1.10.1Multilayer switching for multicast is enabled for router 10.1.10.1.
Complex IP Multicast MLS Network ExamplesThis example consists of the following sections:
• Network Topology Example
• Operation Before IP Multicast MLS Example
• Operation After IP Multicast MLS Example
• Router A (MMLS-RP) Configuration
• Router B (MMLS-RP) Configuration
• Switch A (MMLS-SE) Configuration
• Switch B Configuration
• Switch C Configuration
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Network Topology Example
Figure 49 shows a more complex IP multicast MLS example network topology.
Figure 49 Complex IP Multicast MLS Example Network
The network is configured as follows:
• There are four VLANs (IP subnetworks): VLANs 1, 10, 20, and 30 (VLAN 1 is used only for management traffic, not multicast data traffic).
• The G1 multicast source belongs to VLAN 10.
• Hosts A, C, D, and E have joined IP multicast group G1.
• Switch A is the MMLS-SE.
• Router A and Router B are both operating as MMLS-RPs.
• Port 1/1 on the MMLS-SE is connected to interface fastethernet1/0 on Router A.
• Port 1/2 on the MMLS-SE is connected to interface fastethernet2/0 on Router B.
• The MMLS-SE is connected to the MMLS-RPs through ISL trunk links.
• The trunk link to Router A carries VLANs 1, 10, and 20.
• The trunk link to Router B carries VLANs 1, 10, and 30.
• The subinterfaces on the Router A interface have these IP addresses:
– fastethernet1/0.1: 172.20.1.1 255.255.255.0 (VLAN 1)
– fastethernet1/0.10: 172.20.10.1 255.255.255.0 (VLAN 10)
– fastethernet1/0.20: 172.20.20.1 255.255.255.0 (VLAN 20)
• The subinterfaces on the Router B interface have these IP addresses:
– fastethernet1/0.1: 172.20.1.2 255.255.255.0 (VLAN 1)
– fastethernet2/0.10: 172.20.10.100 255.255.255.0 (VLAN 10)
– fastethernet2/0.30: 172.20.30.100 255.255.255.0 (VLAN 30)
Router A(MMLS-RP)
Router B(MMLS-RP)
ISL trunks VLANs 10, 30VLANs 10, 20
Switch A(MMLS-SE)
VLAN 20172.20.20.0/24
VLAN 30172.20.30.0/24
VLAN 10172.20.10.0/24
C
A B D E F
G1 G1
G1
G1
G1 source
1895
5
Switch B Switch C
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• The default IP multicast MLS management interface is used on both MMLS-RPs (VLAN 1).
• Port 1/3 on the MMLS-SE is connected to Switch B through an ISL trunk link carrying all VLANs.
• Port 1/4 on the MMLS-SE is connected to Switch C through an ISL trunk link carrying all VLANs.
• Switch B and Switch C perform Layer 2 switching functions only.
Operation Before IP Multicast MLS Example
Without IP multicast MLS, when Server A (on VLAN 10) sends traffic destined for IP multicast group G1, Switch B forwards the traffic (based on the Layer 2 multicast forwarding table entry) to Host A on VLAN 10 and to Switch A. Switch A forwards the traffic to the Router A and Router B subinterfaces in VLAN 10.
Router A receives the multicast traffic on its incoming subinterface for VLAN 10, checks the multicast routing table, and replicates the traffic to the outgoing subinterface for VLAN 20. Router B receives the multicast traffic on its incoming interface for VLAN 10, checks the multicast routing table, and replicates the traffic to the outgoing subinterface for VLAN 30.
Switch A receives the traffic on VLANs 20 and 30. Switch A forwards VLAN 20 traffic to the appropriate switch ports (in this case, to Host C), based on the contents of the Layer 2 multicast forwarding table. Switch A forwards the VLAN 30 traffic to Switch C.
Switch C receives the VLAN 30 traffic and forwards it to the appropriate switch ports (in this case, Hosts D and E) using the multicast forwarding table.
Operation After IP Multicast MLS Example
After IP multicast MLS is implemented, when Server A sends traffic destined for multicast group G1, Switch B forwards the traffic (based on the Layer 2 multicast forwarding table entry) to Host A on VLAN 10 and to Switch A.
Switch A checks its Layer 3 multicast MLS cache and recognizes that the traffic belongs to a multicast MLS flow. Switch A does not forward the traffic to the router subinterfaces in VLAN 10 (assuming a completely switched flow). Instead, Switch A replicates the traffic on the appropriate outgoing interfaces (VLANs 20 and 30).
VLAN 20 traffic is forwarded to Host C and VLAN 30 traffic is forwarded to Switch C (based on the contents of the Layer 2 multicast forwarding table). The switch performs a packet rewrite for the replicated traffic so that the packets appear to have been routed by the appropriate router subinterface.
Switch C receives the VLAN 30 traffic and forwards it to the appropriate switch ports (in this case, Hosts D and E) using the multicast forwarding table.
If not all the router subinterfaces are eligible to participate in IP multicast MLS, the switch must forward the multicast traffic to the router subinterfaces in the source VLAN (in this case, VLAN 10). In this situation, on those subinterfaces that are ineligible, the routers perform multicast forwarding and replication in software in the usual manner. On those subinterfaces that are eligible, the switch performs multilayer switching.
Note On both MMLS-RPs, no user-configured IP multicast MLS management interface is specified. Therefore, the VLAN 1 subinterface is used by default.
Configuring IP Multicast Multilayer SwitchingIP Multicast MLS Configuration Examples
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Router A (MMLS-RP) Configurationip multicast-routinginterface fastethernet1/0.1encapsulation isl 1ip address 172.20.1.1 255.255.255.0
interface fastethernet1/0.10encapsulation isl 10ip address 172.20.10.1 255.255.255.0ip pim dense-mode
interface fastethernet1/0.20encapsulation isl 20ip address 172.20.20.1 255.255.255.0ip pim dense-mode
Router B (MMLS-RP) Configurationip multicast-routinginterface fastethernet1/0.1encapsulation isl 1ip address 172.20.1.2 255.255.255.0
interface fastethernet2/0.10encapsulation isl 10ip address 172.20.10.100 255.255.255.0ip pim dense-mode
interface fastethernet2/0.30encapsulation isl 30ip address 172.20.30.100 255.255.255.0ip pim dense-mode
Switch A (MMLS-SE) ConfigurationConsole> (enable) set vlan 10Vlan 10 configuration successfulConsole> (enable) set vlan 20Vlan 20 configuration successfulConsole> (enable) set vlan 30Vlan 30 configuration successfulConsole> (enable) set trunk 1/1 on islPort(s) 1/1 trunk mode set to on.Port(s) 1/1 trunk type set to isl.Console> (enable) set trunk 1/2 on islPort(s) 1/2 trunk mode set to on.Port(s) 1/2 trunk type set to isl.Console> (enable) set trunk 1/3 desirable islPort(s) 1/3 trunk mode set to desirable.Port(s) 1/3 trunk type set to isl.Console> (enable) set trunk 1/4 desirable islPort(s) 1/4 trunk mode set to desirable.Port(s) 1/4 trunk type set to isl.Console> (enable) set igmp enableIGMP feature for IP multicast enabledConsole> (enable) set mls multicast enableMultilayer Switching for Multicast is enabled for this device.Console> (enable) set mls multicast include 172.20.10.1Multilayer switching for multicast is enabled for router 172.20.10.1.Console> (enable) set mls multicast include 172.20.10.100Multilayer switching for multicast is enabled for router 172.20.10.100.Console> (enable)
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Switch B Configuration
The following example shows how to configure Switch B assuming VLAN Trunking Protocol (VTP) is used for VLAN management:
Console> (enable) set igmp enableIGMP feature for IP multicast enabledConsole> (enable)
Switch C Configuration
The following example shows how to configure Switch C assuming VTP is used for VLAN management:
Console> (enable) set igmp enableIGMP feature for IP multicast enabledConsole> (enable)
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Configuring IPX Multilayer Switching
This chapter describes how to configure your network to perform IPX Multilayer Switching (MLS). This chapter contains these sections:
• Prerequisites
• Restrictions
• IPX MLS Configuration Task List
• Troubleshooting Tips
• Monitoring and Maintaining IPX MLS on the Router
• IPX MLS Configuration Examples
For a complete description of the commands in this chapter, refer to the the Cisco IOS Switching Services Command Reference. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
To identify the hardware platform or software image information associated with a feature, use the Feature Navigator on Cisco.com to search for information about the feature or refer to the software release notes for a specific release. For more information, see the section “Finding Additional Feature Support Information” section on page xxxix in the chapter “Using Cisco IOS Software for Release 12.4”
Note The information in this chapter is a brief summary of the information contained in the Catalyst 5000 Series Multilayer Switching User Guide. The commands and configurations described in this guide apply only to the devices that provide routing services. Commands and configurations for Catalyst 5000 series switches are documented in the Catalyst 5000 Series Multilayer Switching User Guide.
PrerequisitesThe following prerequisites must be met before IPX MLS can function:
• A VLAN interface must be configured on both the switch and the router. For information on configuring inter-VLAN routing on the RSM or external router, refer to the Catalyst 5000 Software Configuration Guide, Release 5.1.
• IPX MLS must be configured on the switch. For more information refer to the Catalyst 5000 Software Configuration Guide, Release 5.1 and the Catalyst 5000 Command Reference, Release 5.1.
IPX MLS must be enabled on the router. The minimal configuration steps are described in the section “IPX MLS Configuration Tasks.” For more details on configuring IPX routing, refer to the Cisco IOS AppleTalk and Novell IPX Configuration Guide.
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RestrictionsThis section describes restrictions that apply to configuring IPX MLS on the router.
General Configuration GuidelinesBe aware of the following restrictions:
• You must configure the Catalyst 5000 series switch for IPX MLS to work.
• When you enable IPX MLS, the RSM or externally attached router continues to handle all non-IPX protocols, while offloading the switching of IPX packets to the MLS-SE.
• Do not confuse IPX MLS with NetFlow switching supported by Cisco routers. IPX MLS requires both the RSM or directly attached external router and the MLS-SE, but not NetFlow switching on the RSM or directly attached external router. Any switching path on the RSM or directly attached external router will function (process, fast, optimum, and so on).
External Router GuidelinesWhen using an external router, use the following guidelines:
• Use one directly attached external router per switch to ensure that the MLS-SE caches the appropriate flow information from both sides of the routed flow.
• Use Cisco high-end routers (Cisco 4500, 4700, 7200, and 7500 series) for IPX MLS when they are externally attached to the switch. Make the attachment with multiple Ethernet connections (one per subnet) or by using Fast or Gigabit Ethernet with Inter-Switch Link (ISL) or IEEE 802.1Q encapsulation.
• Connect end hosts through any media (Ethernet, Fast Ethernet, ATM, and FDDI), but connect the external router and the switch only through standard 10/100 Ethernet interfaces, ISL, or IEEE 802.1Q links.
Access List Restrictions The following restrictions apply when you use access lists on interfaces that participate in IPX MLS:
• Input access lists—Router interfaces with input access lists cannot participate in IPX MLS. If you configure an input access list on an interface, no packets inbound or outbound for that interface are Layer 3 switched, even if the flow is not filtered by the access list. Existing flows for that interface are purged, and no new flows are cached.
Note You can translate input access lists to output access lists to provide the same effect on the interface.
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• Output access lists—When an output access list is applied to an interface, the IPX MLS cache entries for that interface are purged. Entries associated with other interfaces are not affected; they follow their normal aging or purging procedures.
Applying access lists that filter according to packet type, source node, source socket, or destination socket prevents the interface from participating in IPX MLS.
Applying access lists that use the log option prevents the interface from participating in IPX MLS.
• Access list impact on flow masks—Access lists impact the flow mask mode advertised to the MLS-SE by an MLS-RP. If no access list has been applied on any MLS-RP interface, the flow mask mode is destination-ipx (the least specific) by default. If an access list that filters according to the source IPX network has been applied, the mode is source-destination-ipx by default.
Restrictions on Interaction of IPX MLS with Other FeaturesIPX MLS affects other Cisco IOS software features as follows:
• IPX accounting—IPX accounting cannot be enabled on an IPX MLS-enabled interface.
• IPX EIGRP—MLS is supported for EIGRP interfaces if the Transport Control (TC) maximum is set to a value greater than the default (16).
Restriction on Maximum Transmission Unit SizeIn IPX the two endpoints of communication negotiate the maximum transmission unit (MTU) to be used. MTU size is limited by media type.
IPX MLS Configuration Task ListTo configure one or more routers for IPX MLS, perform the tasks described in the following sections. The number of tasks you perform depends on your particular configuration.
• Adding an IPX MLS Interface to a VTP Domain (Optional)
• Enabling Multilayer Switching Protocol (MLSP) on the Router (Required)
• Assigning a VLAN ID to a Router Interface (Optional)
• Enabling IPX MLS on a Router Interface (Required)
• Specifying a Router Interface As a Management Interface (Required)
For examples of IPX MLS configurations, see the “IPX MLS Configuration Examples” section later in this document.
Configuring IPX Multilayer SwitchingIPX MLS Configuration Task List
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Adding an IPX MLS Interface to a VTP Domain
Caution Perform this configuration task only if the switch connected to your router interfaces is in a VTP domain. Perform the task before you enter any other IPX MLS interface command—specifically the mls rp ipx or mls rp management-interface command. If you enter these commands before adding the interface to a VTP domain, the interface will be automatically placed in a null domain. To place the IPX MLS interface into a domain other than the null domain, clear the IPX MLS interface configuration before you add the interface to another VTP domain. Refer to the section “Configuration, Verification, and Troubleshooting Tips” and the Catalyst 5000 Software Configuration Guide, Release 5.1.
Determine which router interfaces you will use as IPX MLS interfaces and add them to the same VTP domain as the switches.
To view the VTP configuration and its domain name on the switch, enter the show mls rp vtp-domain EXEC command at the switch Console> prompt.
To assign an MLS interface to a specific VTP domain on the MLS-RP, use the following command in interface configuration mode:
Enabling Multilayer Switching Protocol (MLSP) on the RouterTo enable MLSP on the router, use the following command in global configuration mode:
Assigning a VLAN ID to a Router Interface
Note This task is not required for RSM VLAN interfaces (virtual interfaces), ISL-encapsulated interfaces, or IEEE 802.1Q-encapsulated interfaces.
To assign a VLAN ID to an IPX MLS interface, use the following command in interface configuration mode:
Command Purpose
Router(config-if)# mls rp vtp-domain domain-name Adds an IPX MLS interface to a VTP domain.
Command Purpose
Router(config)# mls rp ipx Globally enables MLSP on the router. MLSP is the protocol that runs between the MLS-SE and MLS-RP.
Command PurposeRouter(config-if)# mls rp vlan-id vlan-id-number Assigns a VLAN ID to an IPX MLS interface.
The assigned IPX MLS interface must be either an Ethernet or Fast Ethernet interface with no subinterfaces.
Configuring IPX Multilayer SwitchingTroubleshooting Tips
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Enabling IPX MLS on a Router InterfaceTo enable IPX MLS on a router interface, use the following command in interface configuration mode:
Specifying a Router Interface As a Management InterfaceTo specify an interface as the management interface, use the following command in interface configuration mode:
Verifying IPX MLS on the RouterTo verify that you have correctly installed IPX MLS on the router, perform the following steps:
Step 1 Enter the show mls rp ipx EXEC command.
Step 2 Examine the output to learn if the VLANs are enabled.
Step 3 Examine the output to learn if the switches are listed by MAC address, indicating they are recognized by the MLS-RP.
Troubleshooting TipsIf you entered either the mls rp ipx interface command or the mls rp management-interface interface command on the interface before assigning it to a VTP domain, the interface will be in the null domain, instead of the VTP domain.
To remove the interface from the null domain and add it to a new VTP domain, use the following commands in interface configuration mode:
Command Purpose
Router(config-if)# mls rp ipx Enables a router interface for IPX MLS.
Command Purpose
Router(config-if)# mls rp management-interface Specifies an interface as the management interface. MLSP packets are sent and received through the management interface. Select only one IPX MLS interface connected to the switch.
Command Purpose
Step 1 Router(config-if)# no mls rp ipxRouter(config-if)# no mls rp management-interfaceRouter(config-if)# no mls rp vtp-domain domain-name
Removes an interface from the null domain.
Step 2 Router(config-if)# mls rp vtp-domain domain-name Adds the interface to a new VTP domain.
Configuring IPX Multilayer SwitchingMonitoring and Maintaining IPX MLS on the Router
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Monitoring and Maintaining IPX MLS on the RouterTo monitor and maintain IPX MLS on the router, use the following command in EXEC mode, as needed:
IPX MLS Configuration ExamplesThis section provides a complex IPX MLS network example: the Cisco 7505 switch over ISL. The example includes router and switch configurations, even though switch commands are not documented in this router publication. The section also includes sample configurations with no access lists and with standard access lists. Refer to the Catalyst 5000 Command Reference, Release 5.1 for more information.
Complex IPX MLS Network ExamplesThis example consists of the following sections:
• IPX MLS Network Topology Example
• Operation Before IPX MLS Example
• Operation After IPX MLS Example
• Switch A Configuration
• Switch B Configuration
• Switch C Configuration
• MLS-RP Configuration
• Router with No Access Lists Configuration
• Configuring a Router with a Standard Access List Example
Command Purpose
Router# mls rp locate ipx Displays information about all switches currently shortcutting for the specified IPX flow(s).
Router# show mls rp interface type number Displays MLS details for a specific interface.
Router# show mls rp ipx Displays details for all IPX MLS interfaces on the router:
• MLS status (enabled or disabled) for switch interfaces and subinterfaces.
• Flow mask required when creating Layer 3 switching entries for the router.
• Current settings for the keepalive timer, retry timer, and retry count.
• MLSP-ID used in MLSP messages.
• List of interfaces in all VTP domains enabled for MLS.
Router# show mls rp vtp-domain domain-name Displays details about IPX MLS interfaces for a specific VTP domain.
Configuring IPX Multilayer SwitchingIPX MLS Configuration Examples
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IPX MLS Network Topology Example
Figure 50 shows an IPX MLS network topology consisting of three Catalyst 5000 series switches and a Cisco 7505 router—all interconnected with ISL trunk links.
Figure 50 Example Network: IPX MLS with Cisco 7505 over ISL
The network is configured as follows:
• There are four VLANs (IPX networks):
– VLAN 1 (management VLAN), IPX network 1
– VLAN 10, IPX network 10
– VLAN 20, IPX network 20
– VLAN 30, IPX network 30
• The MLS-RP is a Cisco 7505 router with a Fast Ethernet interface (interface fastethernet2/0)
• The subinterfaces on the router interface have the following IPX network addresses:
– fastethernet2/0.1–IPX network 1
– fastethernet2/0.10–IPX network 10
– fastethernet2/0.20–IPX network 20
– fastethernet2/0.30–IPX network 30
• Switch A, the MLS-SE VTP server, is a Catalyst 5509 switch with Supervisor Engine III and the NFFC II.
• Switch B and Switch C are VTP client Catalyst 5505 switches.
ISLTrunk link
ISLTrunk link
ISLTrunk link
1/13/1
3/1 3/1
4/11/1
1/11/2 1/3
Catalyst 5505(Switch B)
Catalyst 5505(Switch C)
Catalyst 5509with NFFC
(Switch A, MLS-SE)
Cisco 7505(MLS-RP)
fa2/0
Subinterfaces:fa2/0.1 IPX network 1fa2/0.10 IPX network 10fa2/0.20 IPX network 20fa2/0.30 IPX network 30
Novell clientNC2
Novell serverNS2
Novell serverNS1
VLAN 30IPX network 30
VLAN 10IPX network 10
Novell clientNC1
VLAN 20IPX network 20
2326
1
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Operation Before IPX MLS Example
Before IPX MLS is implemented, when the source host NC1 (on VLAN 10) sends traffic destined for destination server NS2 (on VLAN 30), Switch B forwards the traffic (based on the Layer 2 forwarding table) to Switch A over the ISL trunk link. Switch A forwards the packet to the router over the ISL trunk link.
The router receives the packet on the VLAN 10 subinterface, checks the destination IPX address, and routes the packet to the VLAN 30 subinterface. Switch A receives the routed packet and forwards it to Switch C. Switch C receives the packet and forwards it to destination server NS2. This process is repeated for each packet in the flow between source host NC1 and destination server NS2.
Operation After IPX MLS Example
After IPX MLS is implemented, when the source host NC1 (on VLAN 10) sends traffic destined for destination server NS2 (on VLAN 30), Switch B forwards the traffic (based on the Layer 2 forwarding table) to Switch A (the MLS-SE) over the ISL trunk link. When the first packet enters Switch A, a candidate flow entry is established in the MLS cache. Switch A forwards the packet to the MLS-RP over the ISL trunk link.
The MLS-RP receives the packet on the VLAN 10 subinterface, checks the destination IPX address, and routes the packet to the VLAN 30 subinterface. Switch A receives the routed packet (the enabler packet) and completes the flow entry in the MLS cache for the destination IPX address of NS2. Switch A forwards the packet to Switch C, where it is forwarded to destination server NS2.
Subsequent packets destined for the IPX address of NS2 are multilayer switched by the MLS-SE based on the flow entry in the MLS cache. For example, subsequent packets in the flow from source host NC1 are forwarded by Switch B to Switch A (the MLS-SE). The MLS-SE determines that the packets are part of the established flow, rewrites the packet headers, and switches the packets directly to Switch C, bypassing the router.
Switch A Configuration
This example shows how to configure Switch A (MLS-SE):
SwitchA> (enable) set vtp domain Corporate mode serverVTP domain Corporate modifiedSwitchA> (enable) set vlan 10Vlan 10 configuration successfulSwitchA> (enable) set vlan 20Vlan 20 configuration successfulSwitchA> (enable) set vlan 30Vlan 30 configuration successfulSwitchA> (enable) set port name 1/1 Router LinkPort 1/1 name set.SwitchA> (enable) set trunk 1/1 on islPort(s) 1/1 trunk mode set to on.Port(s) 1/1 trunk type set to isl.SwitchA> (enable) set port name 1/2 SwitchB LinkPort 1/2 name set.SwitchA> (enable) set trunk 1/2 desirable islPort(s) 1/2 trunk mode set to desirable.Port(s) 1/2 trunk type set to isl.SwitchA> (enable) set port name 1/3 SwitchC LinkPort 1/3 name set.SwitchA> (enable) set trunk 1/3 desirable islPort(s) 1/3 trunk mode set to desirable.Port(s) 1/3 trunk type set to isl.
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SwitchA> (enable) set mls enable ipxIPX Multilayer switching is enabled.SwitchA> (enable) set mls include ipx 10.1.1.1IPX Multilayer switching enabled for router 10.1.1.1.SwitchA> (enable) set port name 3/1 Destination D2Port 3/1 name set.SwitchA> (enable) set vlan 20 3/1VLAN 20 modified.VLAN 1 modified.VLAN Mod/Ports---- -----------------------20 3/1 SwitchA> (enable)
Switch B Configuration
This example shows how to configure Switch B:
SwitchB> (enable) set port name 1/1 SwitchA LinkPort 1/1 name set.SwitchB> (enable) set port name 3/1 Source S1Port 3/1 name set.SwitchB> (enable) set vlan 10 3/1VLAN 10 modified.VLAN 1 modified.VLAN Mod/Ports---- -----------------------10 3/1 SwitchB> (enable)
Switch C Configuration
This example shows how to configure Switch C:
SwitchC> (enable) set port name 1/1 SwitchA LinkPort 1/1 name set.SwitchC> (enable) set port name 3/1 Destination D1Port 3/1 name set.SwitchC> (enable) set vlan 30 3/1VLAN 30 modified.VLAN 1 modified.VLAN Mod/Ports---- -----------------------30 3/1 SwitchC> (enable) set port name 4/1 Source S2Port 4/1 name set.SwitchC> (enable) set vlan 30 4/1VLAN 30 modified.VLAN 1 modified.VLAN Mod/Ports---- -----------------------30 3/1 4/1 SwitchC> (enable)
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MLS-RP Configuration
This example shows how to configure the MLS-RP:
mls rp ipxinterface fastethernet 2/0full-duplexmls rp vtp-domain Engineering
interface fastethernet2/0.1encapsulation isl 1ipx address 10.1.1.1 255.255.255.0mls rp ipxmls rp management-interface
interface fastethernet2/0.10encapsulation isl 10ipx network 10mls rp ipx
interface fastethernet2/0.20encapsulation isl 20ipx network 20mls rp ipx
interface fastethernet2/0.30encapsulation isl 30ipx network 30mls rp ipx
Router with No Access Lists Configuration
This example shows how to configure the RSM VLAN interfaces with no access lists. Therefore, the flow mask mode is destination.
Building configuration...
Current configuration:!version 12.0
.
.
.ipx routing 0010.0738.2917mls rp ip mls rp ipx
.
.
.interface Vlan21 ip address 10.5.5.155 255.255.255.0 ipx network 2121 mls rp vtp-domain Engineering mls rp management-interface mls rp ip mls rp ipx!interface Vlan22ip address 10.2.2.155 255.255.255.0 ipx network 2222 mls rp vtp-domain Engineering mls rp ip mls rp ipx!
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.
.
.end
Configuring a Router with a Standard Access List Example
This example shows how to configure a standard access list on the RSM VLAN 3 interface. Therefore, the flow mask mode is destination-source.
Router# show runBuilding configuration...Current configuration:!version 12.0!interface Vlan22ip address 10.2.2.155 255.255.255.0 ipx access-group 800 out ipx network 2222 mls rp vtp-domain Engineering mls rp ip mls rp ipx!
.
.
.!!!
access-list 800 deny 1111 2222access-list 800 permit FFFFFFFF FFFFFFFF
.
.
.end
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