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4-1

Operating Juniper Networks Routers in the Enterprise

Chapter 6: Routing Protocols and Policy

Copyright © 2007 Juniper Networks, Inc. 6-2Education Services

Chapter Objectives

After successfully completing this chapter, you will be able to: •Describe routing tables and route preferences•Describe the role of JUNOS software routing policy•Describe J-Web support for routing protocols and

policy•Configure and monitor static routes•Explain the role of IGPs•Configure and monitor RIP•Configure and monitor OSPF


Agenda:Routing Protocols and PolicyRouting Table and Route Preferences Routing Policy J-Web Support for Routing Protocols and

Policy Configuring and Monitoring Static Routing Interior Gateway Protocols Configuring and Monitoring RIP Configuring and Monitoring OSPF


The Routing Table

Compiles information learned from routing protocols and other routing information sources

Selects an active route to each destination Populates forwarding table Juniper Networks routers maintain multiple routing

tables• inet.0 for IPv4 unicast routing•Others are outside the scope of this course

Direct

RoutingTable

Forwarding

Table

RoutingProtocol

DatabasesOther Routing

Information

Sources

Static

OSPF


Route Preference

Ranks routes received from different sources Primary criterion for selecting the active

route Ranges from 0 to 4,294,967,295, with lower

value preferredRoute Preference Values

Routing Information Source Default Preference

Direct 0Local 0Static 5OSPF internal 10RIP 100Aggregate 130OSPF AS external 150BGP (both EBGP and IBGP) 170


Agenda:Routing Protocols and Policy

Routing Table and Route PreferencesRouting Policy J-Web Support for Routing Protocols and



Routing Policy Overview

Controls routing information transferred into and out of the routing table•Can ignore or change incoming routing information •Can suppress or change outgoing routing information

Policies are made up of match/action pairs •Match conditions can be protocol specific

Apply policy when:•You do not want to import all learned routes into the

routing table•You do not want to advertise all learned routes to

neighboring routers•You want one protocol to receive routes from another

protocol•You want to modify information associated with a

route


Import and Export Policies

Perform policy filtering with respect to the JUNOS software routing table•JUNOS software applies import policy prior to

inclusion in the routing table•JUNOS software applies export policy only to

active routes in the routing table

Neighbors

Protocol

RoutingTable

ForwardingTable

Neighbors

Protocol

ImportRoutes Routes

PFE

Export


Routing Policy Flow

Policies can be chained together•Evaluation proceeds left to right until a terminating

action of accept or reject is reached Individual policies can contain a collection of terms

•Flow-control actions such as next-policy supported

RouteRoute

Term ATerm AAccept

or Reject

Term BTerm B

Term CTerm C

Acceptor Reject

Acceptor Reject

Policy 1

Term ATerm AAccept

or Reject

Term BTerm B

Term CTerm C

Acceptor Reject

Acceptor Reject

Policy 2

Term ATerm AAccept

or Reject

DefaultPolicy

DefaultPolicy

Policy n

Accept

Reject


IGP Default Policies

Protocols are associated with a default policy OSPF:

•Import: Accept all LSAs flooded by that protocol•Export: Reject everything

• LSA flooding announces OSPF-learned and local routes

RIP:•Import: Accept all learned RIP routes, export

nothing•Export: Reject everything

• RIP requires export policy to announce RIP (or other) routes


Agenda:Routing Protocols and Policy Routing Table and Route Preferences Routing PolicyJ-Web Support for Routing Protocols and



J-Web and Routing Protocols (1 of 2)

J-Web routing protocol wizards found at Configuration > Quick Configuration > Routing and Protocols•Quickly establish basic connectivity for:

• Static, RIP, OSPF, and BGP routing


J-Web and Routing Protocols (2 of 2) Use J-Web configuration editor (or the CLI) to:

•Tweak OSPF default route origination, summarization, authentication, etc.•Create

and apply routing policy


Monitoring Routing with J-Web Use J-Web to monitor routing at the Monitor >

Routing page

Displays protocol-specific

information

Displays the

routing table


Sample J-Web Route Table Display

Table name and

summary

Route table contents

Filter display

using these fields


Agenda:Routing Protocols and Policy Routing Table and Route Preferences Routing Policy J-Web Support for Routing Protocols and

PolicyConfiguring and Monitoring Static Routing Interior Gateway Protocols Configuring and Monitoring RIP Configuring and Monitoring OSPF


Static Routing

Static routing is often used when single-homed to a service provider•Static default route directs external traffic to the

service provider

user@host> show route protocol static

inet.0: 8 destinations, 8 routes (8 active, 0 holddown, 0 hidden)+ = Active Route, - = Last Active, * = Both

0.0.0.0/0 *[Static/5] 00:00:15 > via se-0/0/2.0

A default routeNext-hop interface/IP

address

Route source/global preference

Service Provider

Access Routerse-0/0/2

192.168.0/30.1 .2

Static Routing


Use static routing to provide connectivity among all WAN, LAN, and loopback addresses

Static Routing Case Study

WintermuteLondonlo0: 192.168.36.1

se-1/0/1.2 fe-0/0/1.1

fe-0/0/1

.2

se-1/0/0.1

HARLIETokyolo0: 192.168.24.1

10.222.2.0/30

10.222.1.0/30 10.222.3.0/30

(DCE) (DTE)


Default Route Configuration

Access the J-Web static routing wizard at the Configuration > Quick Configuration > Routing and Protocols page•Create a default route on London

Create a default route by

identifying the next-hop IP

address


Static Route Configuration

Static route definitions at Tokyo •Provides reachability to London’s loopback address

and 10.222.3.0/30 network


Confirming Static Routing

Use J-Web or the CLI to display the routing table and to confirm reachability

Both static routes are active at Tokyo

Test traffic sourced from the LAN interface

to confirm end-to-end routing


se-1/0/1.2 fe-0/0/1.1

fe-0/0/1

.2

se-1/0/0.1


10.222.2.0/30

10.222.1.0/30 10.222.3.0/30

(DCE) (DTE)

lab@Tokyo> show route protocol static


10.222.3.0/30 *[Static/5] 00:01:54 > to 10.222.2.2 via se-1/0/0.0192.168.36.1/32 *[Static/5] 00:03:09 > to 10.222.2.2 via se-1/0/0.0

lab@Tokyo> ping source 10.222.1.2 10.222.3.1 count 2PING 10.222.3.1 (10.222.3.1): 56 data bytes64 bytes from 10.222.3.1: icmp_seq=0 ttl=255 time=85.853 ms64 bytes from 10.222.3.1: icmp_seq=1 ttl=255 time=10.049 ms

--- 10.222.3.1 ping statistics ---2 packets transmitted, 2 packets received, 0% packet lossround-trip min/avg/max/stddev = 10.049/47.951/85.853/37.902 ms


Lab 4—Parts 1–3: Static Routing

Configure and monitor static routing. •Note: This lab and future labs require each team

to use the Sydney router, which is logically segmented into several virtual routers. Each student router connects to a virtual router in the form of xx-VR, where xx is a two letter abbreviation for the directly connected student router. Please keep in mind that the command syntax is slightly different when working with a virtual router. Following are some examples:ping routing-instance LO-VR

show route table LO-VR

traceroute routing-instance LO-VR



Policy Configuring and Monitoring Static RoutingInterior Gateway Protocols Configuring and Monitoring RIP Configuring and Monitoring OSPF


Interior Gateway Protocol Overview

IGPs provide internal reachability•Promote connectivity but lack administrative

controls needed to enforce routing policy Normally, link-state routing (OSPF) is deployed

•Optimal convergence and bandwidth usage based on reliable flooding of link-state updates • Builds a replicated network topology database at all

stations within an OSPF area or IS-IS level and uses SPF to find optimal paths

•RIP and static routing are also common

Router A Router B

lo0: 192.168.255.2/32

Router C

lo0: 192.168.255.1/32

lo0: 192.168.255.3/32

Adjacencies

Router A can reach

192.168.255.1, cost 0

Flooded LSAs build link-state database



Policy Configuring and Monitoring Static Routing Interior Gateway ProtocolsConfiguring and Monitoring RIP Configuring and Monitoring OSPF


What Is RIP?

RIP is an IGP that is used within an AS Two versions:

•RIPv1 (RFC 1058)•RIPv2 (RFC 2453)

Primary characteristics:•Distance-vector routing protocol; prone to loops

and slow convergence• Split horizon and poison reverse for loop prevention

•Hop count is used as the metric for path selection, based on Bellman-Ford distance-vector routing algorithm

•Routing updates sent every 30 seconds


RIP V2 Update: 10.222.1.0/30,

cost 1 192.168.24.1/32,

cost 1

RIP Message Types

Two message types:•Request message

• Asks neighbors to send routes•Response message

• Carries route updates• Advertises up to 25 routes per update

Router decides how to handle routes in update•Add, modify, or delete


se-1/0/1.2 fe-0/0/1.1

fe-0/0/1

.2

se-1/0/0.1


10.222.2.0/30

10.222.1.0/30 10.222.3.0/30

(DCE) (DTE)


RIPv2 Features

Backward compatible with RIPv1 Update includes prefix length to support VLSM Authentication on a per-message basis

•Simple password or MD5 authentication Updates sent to multicast address 224.0.0.9

•You can configure broadcast-based updates

192.168.1.128/26

192.168.1.192/26

192.168.1.0/30

192.168.1.4/30

The 192.168.1.0 prefix is subnetted

with a variable-length

netmaskRIP V2 updates

include the netmask in

updates to support VLSM

Update: 192.168.1.192/26,

Cost 1


RIP Limitations

Limitations:•Maximum network diameter = 15 hops•Regular updates include entire routing table

approximately every 30 seconds•Poison reverse increases size of routing updates•Count to infinity slows route-loop prevention•Metrics reflect hop count only•Broadcasts between neighbors (RIPv1 only)•Classful routing means no prefix length carried in

route updates (RIPv1 only)•No authentication mechanism exists (RIPv1 only)•Has poor convergence


Use RIPv2 to provide connectivity among all WAN, LAN, and loopback addresses

RIP Case Study


se-1/0/1.2 fe-0/0/1.1

fe-0/0/1

.2

se-1/0/0.1


10.222.2.0/30

10.222.1.0/30 10.222.3.0/30

(DCE) (DTE)


Configuring RIP: J-Web Use the J-Web Configuration > Quick

Configuration > Routing and Protocols > RIP Routing wizard•Automatically creates export policy to advertise RIP-

enabled interface and learned RIP routes

RIP is enabled

RIP is enabled on LAN, WAN, and loopback interfaces


lab@London# show protocols rip group jweb-rip { export [ jweb-policy-rip jweb-policy-direct ]; neighbor fe-0/0/1.0; neighbor lo0.0; neighbor se-1/0/1.0;}

[edit]lab@London# show policy-options policy-statement jweb-policy-rip { from protocol rip; then accept;}policy-statement jweb-policy-direct { from { protocol direct; interface [ fe-0/0/1.0 lo0.0 se-1/0/1.0 ]; } then accept;}

The Resulting RIP Configuration

Two export policies are in

effect

Export policies override default

behavior by advertising RIP interfaces and

learned RIP routes


Monitoring RIP: J-Web

Use the J-Web Monitor > Routing > RIP Information page to monitor general RIP operation

Two routes learned via RIP

RIP interface paramete

rs


Monitoring RIP Using the CLI (1 of 3)

Show the state of your RIP interfaces using the show rip neighbor command

lab@London> show rip neighbor Source Destination Send Receive InNeighbor State Address Address Mode Mode Met -------- ----- ------- ----------- ---- ------- --- se-1/0/1.0 Up 10.222.2.2 224.0.0.9 mcast both 1lo0.0 Up 192.168.36.1 224.0.0.9 mcast both 1fe-0/0/1.0 Up 10.222.3.1 224.0.0.9 mcast both 1

Show routes learned via RIP using the show route protocol rip command

lab@London> show route protocol rip


10.222.1.0/30 *[RIP/100] 00:21:16, metric 2, tag 0 > to 10.222.2.1 via se-1/0/1.0192.168.24.1/32 *[RIP/100] 00:21:16, metric 2, tag 0 > to 10.222.2.1 via se-1/0/1.0224.0.0.9/32 *[RIP/100] 00:21:22, metric 1 MultiRecv



Display RIP routes advertised out an interface using the show route advertising-protocol rip neighbor command•neighbor is the IP address of local RIP interface

lab@London> show route advertising-protocol rip 10.222.2.2

inet.0: 10 destinations, 10 routes (10 active, 0 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both

10.222.3.0/30 *[Direct/0] 01:19:23 > via fe-0/0/1.0192.168.36.1/32 *[Direct/0] 01:19:23 > via lo0.0

Advertisement of the LAN and loopback addresses owned by London are confirmed on

London’s se-1/0/1 interface



Display RIP routes received on a particular interface using the show route receive-protocol rip neighbor command•neighbor is the IP address of remote RIP neighbor

lab@London> show route receive-protocol rip 10.222.2.1

inet.0: 10 destinations, 10 routes (10 active, 0 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both

10.222.1.0/30 *[RIP/100] 00:27:04, metric 2, tag 0 > to 10.222.2.1 via se-1/0/1.0192.168.24.1/32 *[RIP/100] 00:27:04, metric 2, tag 0 > to 10.222.2.1 via se-1/0/1.0

RIP advertisements for the LAN and loopback addresses owned by Tokyo are confirmed on London’s

se-1/0/1 interface


Lab 4—Parts 4–5: RIP

Configure and monitor RIP version 2.



Policy Configuring and Monitoring Static Routing Interior Gateway Protocols Configuring and Monitoring RIPConfiguring and Monitoring OSPF


OSPF Protocol Overview OSPF is a link-state routing protocol OSPF reliably floods LSAs to distribute link-state

information once an adjacency is formed Each router uses these LSAs to create a

complete database for the network OSPF uses the SPF algorithm within the

database to calculate the best route to every node in the network

JUNOS software support for OSPF includes:•RFC 1587, The OSPF NSSA Option •RFC 2328, OSPF Version 2 •RFC 2740, OSPF for IPv6 •draft-katz-yeung-ospf-traffic-01.txt, Traffic Engineering

Extensions to OSPF •draft-ietf-katz-ward-bfd-00.txt, Bidirectional

Forwarding Detection


OSPF Router Terminology

Internal router has all OSPF links in the same area•Within Area 0, also called a backbone router

Backbone router•Any router with a link to Area 0

ABRs•Routers that belong to more than one area are

called area border routers•Connect OSPF areas to the backbone Area 0

ASBRs•Routers that inject routing information from outside

the OSPF domain are called AS boundary routers


The Designated Router

OSPF elects a DR to represent a broadcast segment•Significantly reduces OSPF traffic on segment•A backup DR is also elected to recover for DR failures

• DROther stations form adjacencies to the DR and BDR only

BDR DR

Adjacencies DROtherDROtherDROther


OSPF Neighbors Versus Adjacencies

DRDROther

DROther

Adjacent

2-way

2-way state to DROther routers is normal

user@host> show ospf neighbor extensive Address Intf State ID Pri Dead172.16.30.254 fe-0/0/0.0 Full 10.250.240.8 128 30 area 0.0.0.5, opt 0x42, DR 172.16.30.254, BDR 172.16.30.253 Up 00:10:50, adjacent 00:10:50

172.16.30.253 fe-0/0/0.0 Full 10.250.240.35 128 30 area 0.0.0.5, opt 0x42, DR 172.16.30.254, BDR 172.16.30.253 Up 00:10:50, adjacent 00:10:52

172.16.30.252 fe-0/0/0.0 2Way 10.250.240.32 64 38 area 0.0.0.5, opt 0x42, DR 172.16.30.254, BDR 172.16.30.253 Up 00:08:10


OSPF Areas (1 of 2)

Areas: •Single AS can be divided into smaller groups called areas•Areas reduce the link-state database because LSA

flooding is now constrained to the area•Routers maintain a separate link-state database on a

per-area basis•Each link-state database within an area must still be

identical on all routers

Backbone(Area 0)

Backbone(Area 0)

Area 1 Area 2


OSPF Areas (2 of 2)

Special OSPF area called the backbone area •Backbone area (0.0.0.0) distributes routing

information between areas•All other OSPF areas must connect to the

backbone area•All user traffic from one area to another must

traverse the backbone

Backbone(Area 0)

Backbone(Area 0)

Area 1 Area 2


OSPF Area Relationships

Backbone

Area 1

Area 3Area 2

(0.0.0.0)

RIP

BGPExternal Routes

Interarea Routes(Summary Routes)

Intra-Area Routes


OSPF Area Types

Stub areas•Do not carry external routes•Cannot contain ASBRs

Totally stubby areas•Stub areas that only receive the default route

from the backbone Not-so-stubby areas

•Allow external routes to be advertised from the area but not received from another area


OSPF Area Types

Backbone

Stub Area

(0.0.0.0)

RIP

BGPExternal Routes

Interarea Routes(Summary Routes) Default Route

Totally Stubby Area

Not-So-StubbyArea

Intra-Area Routes


OSPF LSA Types

NSSA

NSSA External LinksType 7

Used by NSSAa to import external routes into a stub area.

ASBR

External LinksType 5

Originated by an ASBR.Describe destinations external to the AS or a default route to the outside AS.

DR

Network LinksType 2

Originated for multi-access segments with more than one attached router. Describe all routers attached to the specific segment. Originated by a designated router (discussed later).

Router LinksType 1

Describe the state and cost of the router’s links (interfaces) to the area (intra-area).

Summary LinksTypes 3 and 4

Originated by ABRs only.Describe networks in the AS but outside of area (interarea).Also describe the location of the ASBR.

ABR

ASBR


Use a single OSPF area to provide connectivity among all WAN, LAN, and loopback addresses

OSPF Case Study (Single-Area)

OSPF Area 0


se-1/0/1.2 fe-0/0/1.1

fe-0/0/1

.2

se-1/0/0.1


10.222.2.0/30

10.222.1.0/30 10.222.3.0/30

(DCE) (DTE)


Configuring OSPF: J-Web

Use the J-Web OSPF wizard at the Configuration > Quick Configuration > Routing and Protocols page•Configuration goal: A single-area OSPF network using the

sample topology

OSPF process enabled

OSPF enabled on LAN, WAN, and

loopback interfaces

Defaults to lo0

address

Area number and type


The Resulting OSPF Configuration

Default OSPF import and export policies are in effect•Explicit declaration of lo0-based RID requires that

OSPF run on loopback interface• Otherwise, the loopback route will not be advertised

Required because of explicit RID; can be

set to passive

[edit]lab@London# show routing-options router-id 192.168.36.1;

[edit]lab@London# show protocols ospf area 0.0.0.0 { interface fe-0/0/1.0; interface se-1/0/1.0; interface lo0.0;}


Monitoring OSPF: J-Web (1 of 2)

Use the J-Web Monitor > Routing > OSPF Information page to monitor general OSPF operation

OSPF neighbor and interface

status

OSPF protocol statistics


Monitoring OSPF: J-Web (2 of 2)

Use the J-Web Monitor > Routing > Route Information page to monitor OSPF routing information

Current OSPF routes

Filter matches

OSPF routes only


Monitoring OSPF Using the CLI (1 of 5)

Use the show ospf route command to display routes learned and advertised into OSPF• Includes routes for interfaces running OSPF

lab@London> show ospf route ?Possible completions: <[Enter]> Execute this command abr Display OSPF routes to area border routers asbr Display OSPF routes to AS border routers detail Display detailed output extern Display external OSPF routes instance Name of OSPF instance inter Display interarea OSPF routes intra Display intraarea OSPF routes | Pipe through a commandlab@London> show ospf route detail Prefix Path Route NH Metric NextHop Nexthop Type Type Type Interface addr/label192.168.24.1 Intra Router IP 12 se-1/0/1.0 area 0.0.0.0, origin 192.168.24.1 optional-capability 0x0,10.222.1.0/24 Intra Network IP 13 se-1/0/1.0 area 0.0.0.0, origin 192.168.24.1. . .

Use switches to filter by OSPF route (LSA)

type


DR/BDR not elected on point-

to-point links An OSPF neighbor was detected


Use the show ospf interface command to display the OSPF interface parameters•Add the detail or extensive switch for additional

information

lab@London> show ospf interface Interface State Area DR ID BDR ID Nbrsfe-0/0/1.0 DR 0.0.0.0 192.168.36.1 0.0.0.0 0lo0.0 DR 0.0.0.0 192.168.36.1 0.0.0.0 0se-1/0/1.0 PtToPt 0.0.0.0 0.0.0.0 0.0.0.0 1



Use the show ospf neighbor command to display adjacency information

lab@London> show ospf neighbor Address Interface State ID Pri Dead10.222.2.1 se-1/0/1.0 Full 192.168.24.1 128 38

•Clear adjacencies with the clear ospf neighbor command

lab@London> clear ospf neighbor

lab@London> show ospf neighbor Address Interface State ID Pri Dead10.222.2.1 se-1/0/1.0 ExStart 192.168.24.1 128 38



Use the show ospf database command to display entries in the link-state database•Filter the display by LSA type•Use the detail or extensive switches for added

informationlab@London> show ospf database ?Possible completions: <[Enter]> Execute this command advertising-router Router ID of advertising router area OSPF area ID asbrsummary Show summary AS boundary router link-state database brief Display brief output (default) detail Display detailed output extensive Display extensive output extern Show external link-state database . . .

lab@London> show ospf database

OSPF link state database, area 0.0.0.0 Type ID Adv Rtr Seq Age Opt Cksum Len Router 192.168.24.1 192.168.24.1 0x80000005 1375 0x2 0xce62 72Router *192.168.36.1 192.168.36.1 0x80000006 1386 0x2 0x9b79 72

Self-originated LSAs marked with *


Use the clear ospf database command to clear the link-state database•Normally, existing LSAs are simply reflooded over

existing adjacencies•OSPF supports a purge option that forces the

refreshing of all LSAs

lab@London> clear ospf database purge


OSPF link state database, area 0.0.0.0 Type ID Adv Rtr Seq Age Opt Cksum Len Router 192.168.24.1 192.168.24.1 0x80000008 3600 0x2 0xc865 72Router *192.168.36.1 192.168.36.1 0x8000000a 0 0x2 0x937d 72


The purge switch forces all LSAs to the maximum age; the originating router will

refresh the LSA if it is still valid


Lab 4–Part 6: OSPF Single Area

Configure and monitor single-area OSPF.


Use multiple OSPF areas to provide connectivity among all WAN, LAN, and loopback addresses•Authenticate OSPF exchanges between neighbors

OSPF Case Study (Multiarea)

OSPF Area 0


se-1/0/1.2 fe-0/0/1.1

fe-0/0/1

.2

se-1/0/0.1


10.222.2.0/30

10.222.1.0/30 10.222.3.0/30

(DCE) (DTE)

OSPF Area 1 OSPF Area 2


[edit]lab@London# show routing-options router-id 192.168.36.1;

[edit]lab@London# show protocols ospf area 0.0.0.0 { authentication-type md5; interface lo0.0; interface se-1/0/1.0 { authentication { md5 1 key "$9$vW7M7Vg4ZjkPJG"; ## SECRET-DATA } }}area 0.0.0.2 { authentication-type md5; interface fe-0/0/1.0 { authentication { md5 1 key "$9$5T6AB1hrK8Ec"; ## SECRET-DATA } }}

Multiarea OSPF Configuration

Required because of explicit RID; can be set to

passiveArea and interface

configuration

Authentication parameters


Use the show ospf interface command to display the OSPF interface parameters•Add the detail or extensive switch for additional

information

lab@London> show ospf interface Interface State Area DR ID BDR ID Nbrslo0.0 DR 0.0.0.0 192.168.36.1 0.0.0.0 0se-1/0/1.0 PtToPt 0.0.0.0 0.0.0.0 0.0.0.0 1fe-0/0/1.0 DR 0.0.0.2 192.168.36.1 192.168.32.1 1

Monitoring Multiarea OSPF (1 of 2)

Multiple OSPF areas indicates router’s role as

ABR

OSPF neighbors detected



OSPF link state database, Area 0.0.0.0 Type ID Adv Rtr Seq Age Opt Cksum Len Router 192.168.24.1 192.168.24.1 0x80000012 3 0x22 0xb953 60Router *192.168.36.1 192.168.36.1 0x80000015 2 0x22 0x16ce 60Summary 10.222.1.0 192.168.24.1 0x80000008 3 0x22 0xb813 28Summary *10.222.3.0 192.168.36.1 0x80000009 2 0x22 0x4c70 28Summary *192.168.32.1 192.168.36.1 0x80000008 2 0x22 0x59c2 28

OSPF link state database, Area 0.0.0.2 Type ID Adv Rtr Seq Age Opt Cksum Len Router 192.168.32.1 192.168.32.1 0x80000011 3 0x22 0xe5b2 48Router *192.168.36.1 192.168.36.1 0x8000000c 2 0x22 0xf837 36Network *10.222.3.1 192.168.36.1 0x80000007 2 0x22 0xc96 32Summary *10.222.1.0 192.168.36.1 0x80000008 2 0x22 0xdcd6 28Summary *10.222.2.0 192.168.36.1 0x80000009 2 0x22 0xc5ec 28Summary *192.168.24.1 192.168.36.1 0x80000008 2 0x22 0x20f8 28Summary *192.168.36.1 192.168.36.1 0x80000009 2 0x22 0x21f6 28

Monitoring Multiarea OSPF (2 of 2)

Use the show ospf database command to display entries in the link-state database for all areas


Summarize link advertisements on ABR•Summarize the 172.18.12.x/30 routes

from Amsterdam into Area 0 on London

OSPF Case Study (Summarization)

OSPF Area 0


se-1/0/1.2

fe-0/0/1se-1/0/0.1


10.222.2.0/3010.222.3.0/30

(DCE) (DTE)

OSPF Area 2

Amsterdam.1 .2

fe-0/0/1

fe-2/0/0

172.18.12.0/30

172.18.12.4/30

172.18.12.8/30

172.18.12.12/30

lo0: 192.168.32.1



OSPF link state database, Area 0.0.0.0 Type ID Adv Rtr Seq Age Opt Cksum Len Router 192.168.24.1 192.168.24.1 0x80000012 1281 0x22 0xb953 60Router *192.168.36.1 192.168.36.1 0x80000016 837 0x22 0x14cf 60Summary 10.222.1.0 192.168.24.1 0x80000008 1281 0x22 0xb813 28Summary *10.222.3.0 192.168.36.1 0x8000000a 552 0x22 0x4a71 28Summary *172.18.12.0 192.168.36.1 0x80000001 4 0x22 0x5a8a 28Summary *172.18.12.4 192.168.36.1 0x80000001 4 0x22 0x32ae 28Summary *172.18.12.8 192.168.36.1 0x80000001 4 0x22 0xad2 28Summary *172.18.12.12 192.168.36.1 0x80000001 4 0x22 0xe1f6 28Summary *192.168.32.1 192.168.36.1 0x80000009 537 0x22 0x57c3 28

OSPF link state database, Area 0.0.0.2 Type ID Adv Rtr Seq Age Opt Cksum Len Router 192.168.32.1 192.168.32.1 0x80000012 5 0x22 0x6caf 96Router *192.168.36.1 192.168.36.1 0x8000000d 237 0x22 0xf638 36Network *10.222.3.1 192.168.36.1 0x80000007 1280 0x22 0xc96 32Summary *10.222.1.0 192.168.36.1 0x80000008 1280 0x22 0xdcd6 28Summary *10.222.2.0 192.168.36.1 0x80000009 1280 0x22 0xc5ec 28Summary *192.168.24.1 192.168.36.1 0x80000008 1280 0x22 0x20f8 28Summary *192.168.36.1 192.168.36.1 0x80000009 1280 0x22 0x21f6 28

OSPF Database (Before Summarization)


[edit]lab@London# show protocols ospf area 0.0.0.0 { authentication-type md5; interface lo0.0; interface se-1/0/1.0 { authentication { md5 1 key "$9$vW7M7Vg4ZjkPJG"; ## SECRET-DATA } }}area 0.0.0.2 { area-range 172.18.12.0/28; authentication-type md5; interface fe-0/0/1.0 { authentication { md5 1 key "$9$5T6AB1hrK8Ec"; ## SECRET-DATA } }}

Summary Configuration Added

area-range statement will summarize all 172.18.12.x/30

prefixes



OSPF link state database, Area 0.0.0.0 Type ID Adv Rtr Seq Age Opt Cksum Len Router 192.168.24.1 192.168.24.1 0x80000013 818 0x22 0xb754 60Router *192.168.36.1 192.168.36.1 0x80000018 537 0x22 0x10d1 60Summary 10.222.1.0 192.168.24.1 0x80000009 518 0x22 0xb614 28Summary *10.222.3.0 192.168.36.1 0x8000000b 855 0x22 0x4872 28Summary *172.18.12.0 192.168.36.1 0x80000002 855 0x22 0x10df 28Summary *192.168.32.1 192.168.36.1 0x8000000a 855 0x22 0x55c4 28

OSPF link state database, Area 0.0.0.2 Type ID Adv Rtr Seq Age Opt Cksum Len Router 192.168.32.1 192.168.32.1 0x80000013 1165 0x22 0x6ab0 96Router *192.168.36.1 192.168.36.1 0x8000000f 237 0x22 0xf23a 36Network *10.222.3.1 192.168.36.1 0x80000009 538 0x22 0x898 32Summary *10.222.1.0 192.168.36.1 0x8000000b 237 0x22 0xd6d9 28Summary *10.222.2.0 192.168.36.1 0x8000000a 855 0x22 0xc3ed 28Summary *192.168.24.1 192.168.36.1 0x80000009 855 0x22 0x1ef9 28Summary *192.168.36.1 192.168.36.1 0x8000000a 855 0x22 0x1ff7 28

OSPF Database (After Summarization)


Configuring IGP Tracing

Use tracing to debug the operation of your IGP•A typical OSPF tracing configuration:

•Monitor the resulting ospf-trace log file using the monitor start log-file-name or the show log log-file-name CLI commands• Use Esc+q to toggle terminal output when monitoring and monitor stop to discontinue monitoring

•Turn off tracing by deleting the traceoptions stanza

[edit protocols ospf]lab@London# show traceoptions file ospf-trace;flag error detail;flag hello detail;flag lsa-update;


Review Questions

1.Describe the general purpose of routing policy.2.Describe the purpose and role of an IGP.3.What is the default import and export policy for

RIP?4.How can you confirm OSPF adjacency status?5.How can you display only those routes that are

learned by a certain protocol?6.What is the purpose of the ABR and the ASBR?7.Why might OSPF summarization be a good idea?


Lab 4—Part 7: OSPF Multiarea

Configure and monitor multiarea OSPF.Summarize link-state information into Area 0.

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Documents

routing protocols

policy routing table

policy slide

incoming routing information

export policy

import policy

route slide

routes slide