quick start guide - otv v1.4.2

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Quick Start Guide Overlay Transport Virtualization (OTV)Architecture & Solutions GroupUS Public Sector Advanced ServicesMark Stinnette, CCIE Data Center #39151Date 16 October 2013Version 1.4.2 2013 Cisco and/or its affiliates. All rights reserved.#1This presentation will provide end-to-end configurations mapped directly to commonly deployed data center architecture topologies. In this cookbook style; quick start guide; configurations are broken down in an animated step by step process to a complete end-to-end good clean configuration based on Cisco best practices and strong recommendations. Each QSG will contain set the stage content, technology component definitions, recommended best practices, and more importantly different scenario data center topologies mapped directly to complete end-to-end configurations. This QSG is geared for network engineers, network operators, and data center architects to allow them to quickly and effectively deploy these technologies in their data center infrastructure based on proven commonly deployed designs. This Quick Start Guide (QSG) is a Cookbook style guide to Deploying Data Center technologies with end-to-end configurations for several commonly deployed architectures. 2013 Cisco and/or its affiliates. All rights reserved.#2Geographically dispersed data centers provide added application resiliency and workload allocation flexibility. To this end, the network must provide Layer 2, Layer 3 and storage connectivity between data centers. Connectivity must be provided without compromising the autonomy of data centers or the stability of the overall network. OTV provides an operationally optimized solution for the extension of Layer 2 connectivity across any transport. OTV is therefore critical to the effective deployment of distributed data centers to support application availability and flexible workload mobility.

OTV is a "MAC address in IP" technique for supporting Layer 2 VPNs to extend LANs over any transport. The transport can be Layer 2 based, Layer 3 based, IP switched, label switched, or anything else as long as it can carry IP packets. By using the principles of MAC routing, OTV provides an overlay that enables Layer 2 connectivity between separate Layer 2 domains while keeping these domains independent and preserving the fault-isolation, resiliency, and load-balancing benefits of an IP-based interconnection.

Overlay Transport Virtualization (OTV) provides the following benefits:ScalabilityExtends Layer 2 LANs over any network that supports IP (Transport agnostic)Designed to scale across multiple data centersSimplicitySupports transparent deployment over existing network without redesignRequires minimal configuration commandsResiliencyPreserves existing Layer 3 failure boundariesIncludes built-in loop preventionFailure boundary preservation and site independence preservation (failover isolation between data centers)EfficiencyOptimized available bandwidth, by using equal-cost multi-pathing and optimal multicast replicationMultipoint connectivityFast failoverVirtual Machine MobilityOTV ConfigurationBenefits Overview 2013 Cisco and/or its affiliates. All rights reserved.#3Additional benefits of using OTV for Layer 2 extension:

No need for Ethernet over Multiprotocol Label Switching (EoMPLS) or Virtual Private LAN Services (VPLS) deployment for Layer 2 extensions

Use any network transport that supports IP

Provision of Layer 2 and Layer 3 connectivity using the same dark fiber connections

Native Spanning Tree Protocol (STP) isolation: No need to explicitly configure Bridge Data Protocol Unit (BPDU) filtering

Native unknown unicast flooding isolation:Unknown unicast not sent to the overlay

Address Resolution Protocol (ARP) optimization with the OTV ARP cache

Simplified provisioning of First Hop Redundancy Protocol (FHRP) isolation

Simplified addition of sites

OTV ConfigurationBenefits Overview 2013 Cisco and/or its affiliates. All rights reserved.#4

Most Commonly DeployedNo Network Redesign or Re-CablingJoin Interface connects back through the VDC that has the SVIs on themSeparate OTV VDC or Appliance SwitchDedicated Uplink for DCIJoin Interface has a dedicated link out to the DCI transport (Core or WAN Edge)Separate OTV VDC or Appliance SwitchOTV On a StickInline OTVOTV ConfigurationCommonly Deployed Designs :: Aggregation LayerL3 & Join Interfaces

L2 Internal Interfaces

Animation

2013 Cisco and/or its affiliates. All rights reserved.#5

vPC Domain(vPC or vPC+ Supported)Join Interfaces Point-to-Point Layer 3 interfaceM-Series Line Cards OnlyOTV delivers Layer 2 extensions over any type of transport infrastructureAnimationOTV ConfigurationTerminology & ComponentsOTV Edge DevicePerforms OTV FunctionsInternal InterfacesRegular Layer 2 & Carries VLANs extended over OTVPeer-LinkM-Series Line Cards SupportedF1 & F2E Line Cards Supported in 6.2(2)Multicast or UnicastTransports SupportedAuthoritative Edge Device (AED )Even VLANsSVI Separation on the Aggregation VDCAuthoritative Edge Device (AED )Odd VLANsOTV Overlay Interface 2013 Cisco and/or its affiliates. All rights reserved.#6

OTV encapsulates packets into an IP header and where it sets the Don't Fragment (DF) bit for all OTV control and data packets crossing the transport network. The encapsulation adds 42 bytes to the original IP maximum transition unit (MTU) size. So it is a best practice to configure the join interface and all Layer 3 interfaces that face the IP core between the OTV edge devices with the max possible MTU size supported by the transport.Filtering FHRP in both data centers on the OTV VDC is required to allow for existence of the same default gateway in different locations thus optimizing the outbound traffic flows (server to client direction)AnimationOTV ConfigurationTerminology & ComponentsSite ID & Site VLAN are Deployed on Both OTV Edge Devices

Site Identifier ::Use same Site ID within a single data centerUse unique Site ID between different data centers

Site VLAN ::Use same Site VLAN between different data centers (not mandatory) Site VLAN is active on internal interfaces but dont extend Site VLANThe Site VLAN should be a dedicated VLANWEST DCEAST DCHSRP ActiveHSRP StandbyHSRP ActiveHSRP Standby

Filter HSRP

Filter HSRPFilter HSRPFilter HSRPSite ID 1Site VLAN 99Site ID 2Site VLAN 99 2013 Cisco and/or its affiliates. All rights reserved.#7

Layer 3 Interface (Towards Routed Core)

interface ethernet x/ymtu 9216ip address x.x.x.x/30ip router ospf 1 area 0ip ospf network point-to-point ip pim sparse-modeOTV Join Interfaces

interface ethernet x/ymtu 9216ip address x.x.x.x/30ip router ospf 1 area 0ip ospf network point-to-point ip igmp version 3AnimationOTV ConfigurationTerminology & Components :: Layer 2 & Layer 3 FeaturesLayer 3 Interface (Towards OTV Join)

interface ethernet x/zmtu 9216ip address x.x.x.x/30ip router ospf 1 area 0ip ospf network point-to-point ip pim sparse-modeip igmp version 3Aggregation Switch :: Enable PIM

feature pim

ip pim rp-address x.x.x.x group-list 224.0.0.0/4 ip pim ssm range 232.0.0.0/8Aggregation Internal Interfaces

interface port-channel xswitchportswitchport mode trunkswitchport trunk allowed vlan x, yvpc x

interface ethernet x/ychannel-group x force mode activeMust enable Site VLAN [x] on trunk towards the Aggregation Switch[make vlan active]OTV Internal Interfaces

interface port-channel xswitchportswitchport mode trunkswitchport trunk allowed vlan x, y

interface ethernet x/y - zchannel-group x force mode active 2013 Cisco and/or its affiliates. All rights reserved.#8FeatureOverviewEdge DeviceThe OTV Edge Devices performs OTV functions, multiple OTV Edge Devices can exist at each site. OTV requires the Transport Services (TRS) license. If you create the OTV Edge Device in a non default VDC; it requires the Advanced Services license. Internal InterfacesInternal interfaces are the site facing interfaces of the Edge device; carrying VLANs extended through OTV. They are regular Layer 2 interfaces, switch ort mode trunk, and typically port channels in a vPC. No OTV configuration is required on these interfaces. Join InterfacesJoin interfaces are one of the uplink of the Edge device; they are Layer 3 point-to-point routed interfaces (physical interface, port channel, or sub-interface). Its used to physically join the Overlay network. No OTV specific configuration required. Overlay InterfaceVirtual interface is where most of the OTV configuration happens, logical multi-access multicast-capable interface, encapsulates Layer 2 frames in IP unicast or multicast. Authoritative Edge Device (AED)The AED is responsible for MAC address advertisement for its VLANs; forwarding its VLANs traffic inside and outside the site. The extended VLANs are split across the AEDs (even & odd) in OTV multi-homing. Site VLANThe OTV Site VLAN is used to discover OTV neighbor edge devices in same local site.Site Identifier Same site Edge devices must use a common unique Site ID. Site ID is included in the control plane; an overlay will not come up until a Site ID is configured; and should be on all local OTV Edge devices. MTUJoin interfaces and neighboring Core interfaces need to have MTU of 1542 (hard requirement). Best practice to the max possible MTU size supported by the transportFHRP IsolationFiltering FHRP messages across the OTV Overlay allows to provide the same active default gateway in each data center site. Note, in future releases OTV will offer a simple command to enable these filtering capabilities. SVI Separation OTV currently enforces SVI separation for the VLANs being extended across the OTV link, meaning OTV is usually in its own VDC for OTV functions and have SVIs in another Aggregation VDC.OTV ConfigurationAdditional Features, Terminology, & Components 2013 Cisco and/or its affiliates. All rights reserved.#9FeatureOverviewOTV RequirementsNexus 7000 Series or ASR routers. LAN ADVANCED SERVICES (VDC) license & TRANSPORT SERVICES (OTV/LISP) license. An M-Series line card is required in the OTV VDC for OTV functions. Multicast TransportMulticast transport (OTV Control Plane) is ideal for connecting a higher number of sites. OTV Neighbor relationships are built over a multicast enabled core / transport infrastructure. All OTV edge devices can be configured to join a specific ASM (Any Source Multicast) group where they simultaneously play the role of receiver and source. Edge devices join a multicast group; adjacencies are maintained over that multicast group and a single update reaches all neighbors. Unicast TransportSupported since NX-OS release 5.2. Unicast-only transport (OTV Control Plane) is ideal for connecting a small number of sites. Requires the adjacency server. Each OTV devices would need to create multiple copies of each control plane packet and unicast them to each remote OTV device part of the same logical overlay. Adjacency ServerUsed in OTV Unicast mode; usually enabled on an OTV Edge device; can have a primary and secondary; and all other OTV Edge client devices are configured with the address of the adjacency server. The goal is to be able to communicate with all the remote OTV devices, each OTV node needs to know a list of neighbors to replicate the control packets to. Rather than statically configuring in each OTV node the list of all neighbors, a simple dynamic means is used to provide this information; this adjacency server. OTV Extend VLANEnables OTV advertisements for those VLANs. OTV will not forward Layer 2 packets for VLANs not in the extended VLAN range for the overlay interface. Assign a VLAN to only one overlay interface. OTV AuthenticationOTV supports authentication of Hello messages along with authentication of PDUs.Dual Homed OTV Edge DevicesLeverage vPC or vPC+ for dual homed OTV Edge devices. The concept of the AED role along with the site vlan allows multi-homing OTV Edge devices.OTV ConfigurationAdditional Features, Terminology, & Components 2013 Cisco and/or its affiliates. All rights reserved.#10FeatureOverviewSelective Unicast FloodingIn 6.2(2); some applications rely on unknown unicast frames; so selective unicast flooding can be enabled on a per mac address per vlan to accommodate silent or uni-directional hosts. OTV default behavior is no unknown unicast forwarding. Command used: otv flood mac [xxxx.yyyy.zzzz] vlan [#]Dedicated Data Broadcast ForwardingIn 6.2(2); Dedicated broadcast group is a configurable option; useful for QoS purposes. A dedicated multicast group can be configured for all broadcast transmission in an OTV overlay that utilizes multicast transmission on the underlying OTV network. By default, the broadcast and control traffic will share the same multicast group address. The broadcast group needs to be configured on all OTV Edge devices connected to the OTV overlay network. Source Interface with LoopbackIn 6.2(2)+ maintenance release; Logical interfaces as Join Interfaces; Loopback to guarantee interfaces is up/up. An OTV Edge device can be configured to use a loopback interface as the join-interface for an OTV overlay to increase availability. This feature requires the OTV Edge device to participate in the core PIM multicast domain to support multiple paths. Prior to this feature only single homed Ethernet and port channel interface options were available. OTV VLAN TranslationIn 6.2(2); VLAN translation allows OTV to map a local VLAN (in DC 1) to a remote VLAN (in DC 2). In previous NX-OS releases, the extended VLANs had to be identical in each site (ie. X to X). With the VLAN mapping feature, VLANs can be translated, so they can be different in each site (ie. X to Y to Z) providing more flexible deployment options. Both multicast and unicast enabled IP core networks are supported. VLAN mappings have a one-to-one relationship. OTV ConfigurationAdditional Features, Terminology, & Components 2013 Cisco and/or its affiliates. All rights reserved.#11OTV ConfigurationSupported Line Card Topologies :: NX-OS 6.1 and Prior ReleasesOTV VDC must use only M-Series ports for both Internal and Join Interfaces[M1-48, M1-32, M1-08, M2-Series]OTV VDC Types (M-only)Aggregation VDC Types (M-only, M1-F1 or F2/F2E)

Aggregation VDC 2013 Cisco and/or its affiliates. All rights reserved.#12

OTV ConfigurationSupported Line Card Topologies :: NX-OS 6.2 and Later ReleasesOTV VDC Join Interfaces must use only M-Series ports[M1-48, M1-32, M1-08, M2-Series]OTV VDC Internal Interfaces can use M-Series, F1 and F2E ports (F1 and F2E must be in Layer 2 proxy mode)OTV VDC Types (M-only, M1-F1, M1-F2E)Aggregation VDC Types (M-only, M1-F1, M1-F2E, F2, F2E, F2F2E)Aggregation VDC 2013 Cisco and/or its affiliates. All rights reserved.#13Physical View Connectivity MapLayer 3 routed point-to-point interfaces. Will be using OSPF as the routing protocol. Layer 2 interfaces. The Aggregation VDC connects through vPC to the OTV VDC. OTV ConfigurationQuick Start Guide AssumptionsOTV Characteristics2-wide 7k Aggregation VDCMulti-homed OTV VDCMulticast enabled transportExtend VLAN 10OTV Site VLAN 99

2013 Cisco and/or its affiliates. All rights reserved.#14

[Admin / Default VDC]

no vdc combined-hostname

vdc AGG-1 vdc AGG-1 limit-resource module-type m1 f1 m1xl m2xl cpu-share 5 allocate interface Ethernet [.]

vdc OTV-1 vdc OTV-1 limit-resource module-type m1 m1xl m2xl cpu-share 5 allocate interface Ethernet [.]

[Admin / Default VDC] no vdc combined-hostname

vdc AGG-2 vdc AGG-2 limit-resource module-type m1 f1 m1xl m2xl cpu-share 5 allocate interface Ethernet [.]

vdc OTV-2 vdc OTV-2 limit-resource module-type m1 m1xl m2xl cpu-share 5 allocate interface Ethernet [.]

OTV ConfigurationCreate Aggregation & OTV VDCsAllocate the Interfaces to appropriate VDC role accordinglyVerify the Nexus 7000 has the proper licenses to support OTV and VDC.

OTV requires the Transport Services licenseVDC requires the Advanced Services license

install license bootflash:///lan_advanced_services_pkg.licinstall license bootflash:///lan_transport_services_pkg.lic

show license usage

Step 1 :: install | validate licensesStep 2 :: create aggregation VDCStep 3 :: create OTV VDCPerform Configuration Steps at Both DC Sites (East & West)Animation 2013 Cisco and/or its affiliates. All rights reserved.#15

feature lacpfeature vpc

vlan 10-20, 99

spanning-tree pathcost method longspanning-tree port type edge bpduguard defaultspanning-tree port type edge bpdufilter defaultno spanning-tree loopguard default

spanning-tree vlan 10-20, 99 priority 0spanning-tree pseudo-information vlan 10-20 root priority 4096 vlan 1-10, 99 designated priority 8192 vlan 11-20 designated priority 16384

vpc domain 1 role priority 1 system-priority 4096 peer-keepalive destination [.] source [.] vrf management peer-switch peer-gateway auto-recovery auto-recovery reload-delay delay restore 30 ip arp synchronize

interface port-channel 2 switchport switchport mode trunk switchport trunk allowed vlan 10-20, 99 spanning-tree port type network vpc peer-link interface e3/1 , e4/1 channel-group 2 force mode active

feature lacpfeature vpc

vlan 10-20, 99

spanning-tree pathcost method longspanning-tree port type edge bpduguard defaultspanning-tree port type edge bpdufilter defaultno spanning-tree loopguard default

spanning-tree vlan 10-20, 99 priority 0spanning-tree pseudo-information vlan 10-20, 99 root priority 4096 vlan 1-10, 99 designated priority 16384 vlan 11-20 designated priority 8192

vpc domain 1 role priority 2 system-priority 4096 peer-keepalive destination [.] source [.] vrf management peer-switch peer-gateway auto-recovery auto-recovery reload-delay delay restore 30 ip arp synchronize

interface port-channel 2 switchport switchport mode trunk switchport trunk allowed vlan 10-20, 99 spanning-tree port type network vpc peer-link interface e3/1 , e4/1 channel-group 2 force mode activeSee QSG :: vPC for more details OTV ConfigurationConfigure Aggregation VDC :: Layer 2 vPC (Option)Perform Configuration Steps at Both DC Sites (East & West)Animation 2013 Cisco and/or its affiliates. All rights reserved.#16

feature lacpfeature vpcinstall feature-set fabricpathfeature-set fabricpath

vlan 10-20, 99mode fabricpath

fabricpath switch-id 10

fabricpath domain default root-priority 255

spanning-tree pseudo-information vlan 10-20, 99 root priority 0

vpc domain 1 role priority 1 system-priority 4096 peer-keepalive destination [.] source [.] vrf management peer-gateway auto-recovery auto-recovery reload-delay delay restore 30 ip arp synchronize fabricpath switch-id 1000

interface port-channel 2 switchport mode fabricpath vpc peer-link interface e3/1 , e4/1 channel-group 2 force mode active

feature lacpfeature vpcinstall feature-set fabricpathfeature-set fabricpath

vlan 10-20, 99 mode fabricpath

fabricpath switch-id 11

fabricpath domain default root-priority 254

spanning-tree pseudo-information vlan 10-20, 99 root priority 0

vpc domain 1 role priority 2 system-priority 4096 peer-keepalive destination [.] source [.] vrf management peer-gateway auto-recovery auto-recovery reload-delay delay restore 30 ip arp synchronize fabricpath switch-id 1000

interface port-channel 2 switchport mode fabricpath vpc peer-link interface e3/1 , e4/1 channel-group 2 force mode activeSee QSG :: FabricPath for more details OTV ConfigurationConfigure Aggregation VDC :: Layer 2 FabricPath vPC+ (Option)Default / Admin VDC OnlyDefault / Admin VDC OnlyPerform Configuration Steps at Both DC Sites (East & West)Animation 2013 Cisco and/or its affiliates. All rights reserved.#17

feature ospffeature interface-vlanfeature hsrp

vlan 10 20, 99

interface loopback0 ip address [.]/32

router ospf 1 router-id [.] log-adjacency-changes detail auto-cost reference-bandwidth 100Gbps

interface e1/1 ip address [.]/30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

interface e1/10 ip address [.]/30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point interface vlan 10 ip address 10.10.10.2/24 no ip redirects ip router ospf 1 area 0.0.0.0 ip ospf passive-interface hsrp 1 preempt priority 110 ip 10.10.10.1

feature ospffeature interface-vlanfeature hsrp

vlan 10 20, 99

interface loopback0 ip address [.]/32

router ospf 1 router-id [.] log-adjacency-changes detail auto-cost reference-bandwidth 100Gbps

interface e1/1 ip address [.]/30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

interface e1/10 ip address [.]/30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point interface vlan 10 ip address 10.10.10.3/24 no ip redirects ip router ospf 1 area 0.0.0.0 ip ospf passive-interface hsrp 1 preempt ip 10.10.10.1

OTV ConfigurationConfigure Aggregation VDC :: Layer 3 Infrastructure Allocate the following accordingly ::IP addressingOSPF areasSVIs & HSRP GroupsPerform Configuration Steps at Both DC Sites (East & West)Animation 2013 Cisco and/or its affiliates. All rights reserved.#18

feature ospffeature lacpfeature vpc

interface e 1/2 ip address [.] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

interface port-channel 10 switchport switchport mode trunk switchport trunk allowed vlan 10, 99 vpc 10

interface port-channel 20 switchport switchport mode trunk switchport trunk allowed vlan 10, 99 vpc 20

interface e5/1 channel-group 10 force mode active

interface e6/1 channel-group 20 force mode active

feature ospffeature lacpfeature vpc

interface e 1/2 ip address [.] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

interface port-channel 10 switchport switchport mode trunk switchport trunk allowed vlan 10, 99 vpc 10

interface port-channel 20 switchport switchport mode trunk switchport trunk allowed vlan 10, 99 vpc 20

interface e5/1 channel-group 10 force mode active

interface e6/1 channel-group 20 force mode active

OTV ConfigurationConfigure OTV :: Layer 2 & Layer 3 Infrastructure @ Aggregation Step 1 :: configure L3 link towards OTV Join InterfaceStep 2 :: configure L2 vPC towards OTV Internal InterfacePerform Configuration Steps at Both DC Sites (East & West)AnimationThe OTV internal interfaces carry the VLANs to be extended and the OTV site VLAN (used within the data center to provide multi-homing). They behave as regular Layer 2 switch port trunk interfaces; in fact, they send, receive, and process the Spanning Tree Protocol BPDUs as they would on a regular LAN bridge device. 2013 Cisco and/or its affiliates. All rights reserved.#19

OTV ConfigurationConfigure OTV :: Layer 2 & Layer 3 Infrastructure @ OTV VDCStep 1 :: configure OTV Join InterfacesStep 2 :: configure OTV Internal InterfacesStep 3 :: create vlan to extend Perform Configuration Steps at Both DC Sites (East & West)feature ospffeature lacp

vlan 10

spanning-tree vlan 10 priority 32768

interface loopback0 ip address [.]/32

router ospf 1 router-id [.] log-adjacency-changes detail auto-cost reference-bandwidth 100Gbps

interface e 1/9 ip address [.] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

interface port-channel 10 switchport switchport mode trunk switchport trunk allowed vlan 10

interface e2/1, e2/2 channel-group 10 force mode activefeature ospffeature lacp

vlan 10

spanning-tree vlan 10 priority 32768

interface loopback0 ip address [.]/32

router ospf 1 router-id [.] log-adjacency-changes detail auto-cost reference-bandwidth 100Gbps

interface e 1/9 ip address [.] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

interface port-channel 10 switchport switchport mode trunk switchport trunk allowed vlan 10

interface e2/1, e2/2 channel-group 10 force mode active

Animation 2013 Cisco and/or its affiliates. All rights reserved.#20

OTV ConfigurationConfigure OTV :: Enable Jumbo MTUStep 1 :: increase MTU on Join InterfacesStep 2 :: increase MTU on all Layer 3 InterfacesPerform Configuration Steps at Both DC Sites (East & West)feature ospffeature lacpfeature vpc

vlan 10

interface e 1/9 mtu 9216 ip address [.] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point feature ospffeature lacpfeature vpc

vlan 10

interface e 1/9 mtu 9216 ip address [.] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

feature ospffeature lacpfeature vpc

vlan 10 20, 99

interface e 1/2 mtu 9216 ip address [.] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

interface e1/10 mtu 9216 ip address [.]/30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

interface e1/1 mtu 9216 ip address [.]/30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

feature ospffeature lacpfeature vpc

vlan 10 20, 99

interface e 1/2 mtu 9216 ip address [.] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

interface e1/10 mtu 9216 ip address [.]/30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

interface e1/1 mtu 9216 ip address [.]/30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

Animation 2013 Cisco and/or its affiliates. All rights reserved.#21

OTV ConfigurationConfigure OTV :: Enable Required Multicast Step 1 :: enable PIM Step 2 :: configure PIM sparse mode [AGG VDC](on all intra & inter data center Layer 3 links)Step 3 :: configure IGMP v3 [AGG & OTV VDC](join interfaces only)Step 4 :: configure Rendezvous Point (RP) Step 5 :: configure Source-Specific Multicast (SSM)Perform Configuration Steps at Both DC Sites (East & West)interface e 1/9 mtu 9216 ip address [.] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point ip igmp version 3 interface e 1/9 mtu 9216 ip address [.] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point ip igmp version 3

feature ospffeature lacpfeature vpcfeature pim

ip pim rp-address [x.x.x.x] group-list 224.0.0.0/4 ip pim ssm range 232.0.0.0/8

interface e1/1 mtu 9216 ip address [.]/30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point ip pim sparse-mode

interface e 1/2 mtu 9216 ip address [.] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point ip pim sparse-mode ip igmp version 3

interface e1/10 mtu 9216 ip address [.]/30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point ip pim sparse-modefeature ospffeature lacpfeature vpcfeature pim

ip pim rp-address [x.x.x.x] group-list 224.0.0.0/4 ip pim ssm range 232.0.0.0/8

interface e1/1 mtu 9216 ip address [.]/30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point ip pim sparse-mode

interface e 1/2 mtu 9216 ip address [.] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point ip pim sparse-mode ip igmp version 3

interface e1/10 mtu 9216 ip address [.]/30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point ip pim sparse-mode

Animation 2013 Cisco and/or its affiliates. All rights reserved.#22

OTV ConfigurationFinish OTV Configuration :: Overlay, Site-ID, Site-VLANfeature otv

vlan 10

otv site-vlan 99otv site-identifier 0000.0000.0002

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv extend-vlan 10

interface port-channel 10 switchport switchport mode trunk switchport trunk allowed vlan 10feature otv

vlan 10

otv site-vlan 99otv site-identifier 0000.0000.0001

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv extend-vlan 10 interface port-channel 10 switchport switchport mode trunk switchport trunk allowed vlan 10

feature otv

vlan 10

otv site-vlan 99otv site-identifier 0000.0000.0001

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv extend-vlan 10

interface port-channel 10 switchport switchport mode trunk switchport trunk allowed vlan 10

interface e2/1, e2/2 channel-group 10 force mode active

feature otv

vlan 10

otv site-vlan 99otv site-identifier 0000.0000.0002

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv extend-vlan 10

interface port-channel 10 switchport switchport mode trunk switchport trunk allowed vlan 10

interface e2/1, e2/2 channel-group 10 force mode active

Site ID 1Site VLAN 99Site ID 2Site VLAN 99Step 1 :: enable OTV featureStep 2 :: configure site-vlanStep 3 :: enable site-vlan on L2 trunks (make vlan active)Step 4 :: configure site-identifier Step 5 :: configure OTV Overlay InterfaceSite ID 1Site VLAN 99Site ID 2Site VLAN 99Animationinterface e2/1, e2/2 channel-group 10 force mode active

interface e2/1, e2/2 channel-group 10 force mode active

, 99, 99, 99, 99, 99, 99, 99, 99OTV Characteristics2-wide 7k Aggregation VDCMulti-homed OTV VDCMulticast enabled transportExtend VLAN 10

2013 Cisco and/or its affiliates. All rights reserved.#23

OTV ConfigurationOTV ConfigurationAnimationThe Layer 2 links are known as internal interfaces and are used by the OTV edge device to learn the MAC addresses of the site and forward Layer 2 traffic across the sites for the extended VLANs. The Layer 3 link is known as the join interface, which OTV uses to perform IP-based virtualization to send and receive overlay traffic between sites. The IP address of this interface is used to advertise reachability of a MAC addresses present in the site. There is one Join interface per OTV Overlay; however, if multiple Layer 3 interfaces are present on the OTV edge device, the unicast extended traffic can get routed over any of these linksOTV encapsulates packets into an IP header and where it sets the Don't Fragment (DF) bit for all OTV control and data packets crossing the transport network. The encapsulation adds 42 bytes to the original IP maximum transition unit (MTU) size. So it is a best practice to configure the join interface and all Layer 3 interfaces that face the IP core between the OTV edge devices with the max possible MTU size supported by the transport. OTV uses site VLAN to allow multiple OTV edge devices within the site to talk to each other and determine the AED for the OTV-extended VLANs. It is a best practice to use a dedicated VLAN as site VLAN. The site VLAN should not be extended and should be carried down to the aggregation layer across the VPC peer link. Site ID 1Site VLAN 99NOTESThe OTV edge device is also configured with the overlay interface, which is associated with the join interface to provide connectivity to the physical transport network. The overlay interface is used by OTV to send and receive Layer 2 frames encapsulated in IP packets. From the perspective of MAC-based forwarding on the site, the overlay interface is simply another bridged interface. However, no Spanning Tree Protocol packets or unknown unicast packets are forwarded over the overlay interface.Note: The overlay interface does not come up until you configure a multicast group address and the site-VLAN has at least an active port on the device.A VLAN is not advertised on the overlay network; therefore, forwarding cannot occur over the overlay network unless the VLANs are explicitly extended. Once the VLAN is extended, the OTV edge device will begin advertising locally learned MAC addresses on the overlay network.Key advantages of using multicast is that it allows optimal multicast traffic replication to multiple sites and avoids head-end replication that leads to suboptimal bandwidth utilization.When sites are multihomed with OTV EDs, separation is achieved by electing an authoritative edge device (AED) for each VLAN in the same site (site-id), which is the only device that can forward the traffic for the extended VLAN inside and outside the data center. The extended VLANs are split in odd and even and automatically assigned to the site's edge devices.The multicast control group identifies the overlay; two different overlays must have two different multicast control groups. The control group is used for neighbor discovery and to exchange MAC address reachability. The data group however is an SSM (Source Specific Group) group range, which is used to carry multicast data traffic generated by the sitesIn the aggregation layer, Protocol Independent Multicast (PIM) is configured on all intra- and inter-data-center Layer 3 links to allow multicast states to be built in the core network.Since PIM sparse mode requires a rendezvous point (RP) to build a multicast tree, one of the aggregation switches in each data center is used as an RP. Local RP allows both local sources and receivers to join local RP rather than having to go to different data center to reach an RP in order to build a shared tree. For more information about MSDP and Anycast features of multicast, visit:http://www.cisco.com/en/US/docs/ios/solutions_docs/ip_multicast/White_papers/anycast.html 2013 Cisco and/or its affiliates. All rights reserved.#24

OTV ConfigurationOTV Configuration :: Unicast-Only Mode feature otv

vlan 10, 99

otv site-vlan 99otv site-identifier 0000.0000.0002

interface Overlay 1 otv join-interface ethernet 1/9 otv use-adjacency-server [x] [y] unicast-only otv extend-vlan 10

interface e 1/9 mtu 9216 ip address [z] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-pointfeature otv

vlan 10, 99

otv site-vlan 99otv site-identifier 0000.0000.0001

interface Overlay 1 otv join-interface ethernet 1/9 otv use-adjacency-server [x] [y] unicast-only otv extend-vlan 10

interface e 1/9 mtu 9216 ip address [w] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-pointfeature otv

vlan 10, 99

otv site-vlan 99otv site-identifier 0000.0000.0001

interface Overlay 1 otv join-interface ethernet 1/9 otv adjacency-server unicast-only otv extend-vlan 10

interface e 1/9 mtu 9216 ip address [x] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-pointfeature otv

vlan 10, 99

otv site-vlan 99otv site-identifier 0000.0000.0002

interface Overlay 1 otv join-interface ethernet 1/9 otv adjacency-server unicast-only otv use-adjacency-server [x] unicast-only otv extend-vlan 10

interface e 1/9 mtu 9216 ip address [y] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

Site ID 1Site VLAN 99Site ID 2Site VLAN 99Step 1 :: enable OTVStep 2 :: configure site-vlan, site-id, Overlay InterfaceStep 3 :: define role of adjacency server [primary]Step 4 :: define role of adjacency server [secondary]Step 5 :: define all other edge devices as clientsSite ID 1Site VLAN 99Site ID 2Site VLAN 99AnimationPrimary Adjacency ServerSecondary Adjacency ServerAssume :: enable site-vlan on L2 trunks (make vlan active)

interface port-channel 10 switchport switchport mode trunk switchport trunk allowed vlan 10, 99Primary Adjacency Server :: Join Interface [x]Secondary Adjacency Server :: Join Interface [y]

2013 Cisco and/or its affiliates. All rights reserved.#25

OTV ConfigurationOTV Configuration :: Unicast-Only Mode feature otv

vlan 10, 99

otv site-vlan 99otv site-identifier 0000.0000.0001

interface Overlay 1 otv join-interface ethernet 1/9 otv use-adjacency-server [x] [y] unicast-only otv extend-vlan 10

interface e 1/9 mtu 9216 ip address [w] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-pointfeature otv

vlan 10, 99

otv site-vlan 99otv site-identifier 0000.0000.0001

interface Overlay 1 otv join-interface ethernet 1/9 otv adjacency-server unicast-only otv extend-vlan 10

interface e 1/9 mtu 9216 ip address [x] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-pointfeature otv

vlan 10, 99

otv site-vlan 99otv site-identifier 0000.0000.0002

interface Overlay 1 otv join-interface ethernet 1/9 otv adjacency-server unicast-only otv use-adjacency-server [x] unicast-only otv extend-vlan 10

interface e 1/9 mtu 9216 ip address [y] / 30 ip router ospf 1 area 0.0.0.0 ip ospf network point-to-point

Primary Adjacency ServerSecondary Adjacency ServerPrimary Adjacency Server :: Join Interface [x]Secondary Adjacency Server :: Join Interface [y]

Two pieces of configuration are required to deploy OTV across a unicast-only transport infrastructure: first, it is required to define the role of Adjacency Server; whereas the other piece of configuration is required in each OTV edge device not acting as an Adjacency Server (i.e acting as a client). All client OTV edge devices are configured with the address of the Adjacency Server. All other adjacency addresses are discovered dynamically. Thereby, when a new site is added, only the OTV edge devices for the new site need to be configured with the Adjacency Server addresses. No other sites need additional configuration.

The recommendation is usually to deploy a redundant pair of Adjacency Servers in separate DC sites.The configuration on the Primary Adjacency Server is very simple and limited to enable AS functionality (otv adjacency-server command). The same command is also required on the Secondary Adjacency Server device, but also needs to point to the Primary AS (leveraging the otv use-adjacency-server command). Finally, the generic OTV Edge Device must be configured to use both the Primary and Secondary Adjacency Servers. The sequence of adjacency server address in the configuration determine primary or secondary adjacency server role. This order is relevant since an OTV edge device will always use the OTV neighbor-list (oNL) provided by the Primary Adjacency Server, unless it detects that specific device is not available anymore (control plane Hellos are always exchanged as keepalives between each OTV device and the Adjacency Servers). NOTESAnimation 2013 Cisco and/or its affiliates. All rights reserved.#26ip access-list ALL_IPs 10 permit ip any any mac access-list ALL_MACs 10 permit any any ip access-list HSRP_IP 10 permit udp any 224.0.0.2/32 eq 1985 20 permit udp any 224.0.0.102/32 eq 1985 mac access-list HSRP_VMAC 10 permit 0000.0c07.ac00 0000.0000.00ff any 20 permit 0000.0c9f.f000 0000.0000.0fff any arp access-list HSRP_VMAC_ARP 10 deny ip any mac 0000.0c07.ac00 ffff.ffff.ff00 20 deny ip any mac 0000.0c9f.f000 ffff.ffff.f000 30 permit ip any mac any

feature dhcp ip arp inspection filter HSRP_VMAC_ARP vlan 10

vlan access-map HSRP_Localization 10 match mac address HSRP_VMAC match ip address HSRP_IP action drop vlan access-map HSRP_Localization 20 match mac address ALL_MACs match ip address ALL_IPs action forward

vlan filter HSRP_Localization vlan-list 10

mac-list OTV_HSRP_VMAC_deny seq 10 deny 0000.0c07.ac00 ffff.ffff.ff00 mac-list OTV_HSRP_VMAC_deny seq 11 deny 0000.0c9f.f000 ffff.ffff.f000 mac-list OTV_HSRP_VMAC_deny seq 20 permit 0000.0000.0000 0000.0000.0000

route-map OTV_HSRP_filter permit 10 match mac-list OTV_HSRP_VMAC_deny feature otv

vlan 10, 99

otv site-vlan 99otv site-identifier 0000.0000.0001

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv extend-vlan 10

interface port-channel 10 description ** OTV Internal Interface ** switchport switchport mode trunk switchport trunk allowed vlan 10, 99 mac packet-classify

otv-isis default vpn Overlay1 redistribute filter route-map OTV_HSRP_filter Step 1 :: create OTV HSRP access-lists (VACL)Step 2 :: create OTV HSRP localization filtersFilter out HSRP v1 and v2Filter out Gratuitous ARPStep 3 :: create route-map to prevent advertisements of HSRP VMACs AnimationOTV ConfigurationOTV Configuration :: HSRP Filtering The filtering of FHRP messages across the overlay is a critical functionality to be enabled, because it allows applying the same FHRP configuration in different sites. The end result is that the same default gateway is available (i.e. characterized by the same virtual IP and virtual MAC addresses) in each data center. This capability optimizes the outbound traffic flows (server to client direction); but this does not solve the mechanism to control and improve the ingress traffic (client to server direction) as traffic will continue to go via the original DC; solutions to solve this challenge include DNS Based, Route Injection, or LISP. The VLAN ACL is required to identify the traffic that needs to be filtered. This configuration applies to the HSRP v1 & v2 (bold) protocols. After applying theEven though HSRP traffic is filtered via the VACL, the vMAC used to source the HSRP packets is still learned by the OTV VDC. Therefore, OTV advertises this MAC address information to the other sites via an IS-IS update. While this in itself is not causing harm, it would cause the remote OTV the edge devices to see constant MAC moves happening for the vMAC (from the internal interface to the overlay interface and vice versa). IP ACL's to drop HSRP Hellos and forward other trafficMAC ACL's to drop non-IP HSRP traffic and forward other traffic Create the VACL & apply the VACL to each extended vlan Feature dhcp required for ARP inspection & create the ARP access-list to deny traffic from the Virtual MAC & apply ARP ACL to each extended VLAN Create mac-list to deny advertising of virtual MAC, create the route-map, and apply the route-map to each overlay configuration on the OTV VDC to the set of VLANs that are trunked from the Agg VDC to the OTV VDC, all HSRP messages will be dropped once received by the OTV VDC. It is also required to apply a specific filter to ensure suppression of the Gratuitous ARP (GARP) messages that may be received across the OTV Overlay from the remote sites. 2013 Cisco and/or its affiliates. All rights reserved.#27

feature otv

vlan 10, 99

key chain OTV-Key key 1 key-string 0 Cisc0!

otv site-vlan 99otv site-identifier 0000.0000.0001

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv extend-vlan 10 otv isis authentication-type md5 otv isis authentication key-chain OTV-Key

otv-isis default vpn Overlay1 authentication-check authentication-type md5 authentication key-chain OTV-Key

Step 1 :: configure OTV key chainStep 2 :: apply md5 authentication to OTV HellosStep 3 :: apply md5 authentication to OTV PDUsAnimationOTV ConfigurationOTV Configuration :: Authentication OTV supports authentication of Hello messages along with authentication of Protocol Data Units (PDU)sfeature otv

vlan 10, 99

key chain OTV-Key key 1 key-string 0 Cisc0!

otv site-vlan 99otv site-identifier 0000.0000.0001

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv extend-vlan 10 otv isis authentication-type md5 otv isis authentication key-chain OTV-Key

otv-isis default vpn Overlay1 authentication-check authentication-type md5 authentication key-chain OTV-KeyPerform Configuration Steps at Both DC Sites (East & West) 2013 Cisco and/or its affiliates. All rights reserved.#28

feature otv

vlan 10, 99, 100

otv site-vlan 99otv site-identifier 0000.0000.0001

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv extend-vlan 10 otv vlan mapping 10 to 100Step 1 :: configure vlan mappingAnimationOTV ConfigurationOTV VLAN Translation :: Translation Through Transit VLANWhen a different VLAN is used at multiple sitesA mapped VLAN can not be extended on another siteVLAN mappings have a one-to-one relationshipVLAN mappings can be added or removed without impacting all mappings on the overlay interfacefeature otv

vlan 20, 99, 100

otv site-vlan 99otv site-identifier 0000.0000.0002

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv extend-vlan 20 otv vlan mapping 20 to 100VLAN 10VLAN 20VLAN 100 2013 Cisco and/or its affiliates. All rights reserved.#29

feature otv

vlan 10, 99

interface loopback 10 ip address [.]/32

otv site-vlan 99otv site-identifier 0000.0000.0001

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv broadcast-group 224.2.2.0 otv extend-vlan 10 Step 1 :: configure broadcast groupAnimationOTV ConfigurationOTV Configuration :: Dedicated Broadcast Groupotv broadcast-group configuration line under overlayOptional commandUseful for QoS purposesThe broadcast group needs to be configured for all OTV Edge Devices connected to the OTV Overlay networkfeature otv

vlan 10, 99

interface loopback 10 ip address [.]/32

otv site-vlan 99otv site-identifier 0000.0000.0001

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv broadcast-group 224.2.2.0 otv extend-vlan 10 Perform Configuration Steps at Both DC Sites (East & West) 2013 Cisco and/or its affiliates. All rights reserved.#30

feature otv

vlan 10, 99

otv site-vlan 99otv site-identifier 0000.0000.0001

otv flood mac 1111.2222.0101 vlan 10

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv extend-vlan 10 Step 1 :: configure static OTV flood [enabled per mac address]

AnimationOTV ConfigurationOTV Configuration :: Selective Unicast FloodingNormally, unknown unicast Layer 2 frames are not flooded between OTV sites, and MAC addresses are not learned across the overlay interface. Any unknown unicast messages that reach the OTV edge device are blocked from crossing the logical overlay, allowing OTV to prevent Layer 2 faults from spreading to remote sites.

The end points connected to the network are assumed to not be silent or unidirectional. However, some data center applications require the unknown unicast traffic to be flooded over the overlay to all the data centers, where end points may be silent. Beginning with Cisco NX-OS Release 6.2(2), you can configure selective unicast flooding to flood the specified destination MAC address to all other edge devices in the OTV overlay network with that unknown unicast traffic.UnknownUnicastfeature otv

vlan 10, 99

otv site-vlan 99otv site-identifier 0000.0000.0002

interface Overlay 1 otv join-interface ethernet 1/9 otv control-group 239.1.1.1 otv data-group 232.1.1.0/24 otv extend-vlan 10MAC 1 MAC 2

2013 Cisco and/or its affiliates. All rights reserved.#31OTV encapsulation is done on M-series modules

Note: The control-plane protocol used by OTV is IS-IS. However, IS-IS does not need to be explicitly configured. It runs in the background once OTV is enabled.

In a multi-tenancy environment, the same OTV VDC can be configured with multiple overlays to provide a segmented Layer 2 extension for different tenants or applications.

When multiple data center sites are interconnected, the OTV operations can benefit from the presence of multicast in the core. Multicast is not mandatory in most OTV topologies (number of sites) since you can use the unicast-mode as well.

The same OTV VDCs can be used by multiple VDCs deployed at the aggregation tier, as well as by other Layer 2 switches connected to the OTV VDCs. This is done by configuring multiple OTV overlays. It's important to note that the extended VLANs within these multiple overlays should not overlap.

A separate Layer 3 link between the two aggregation VDCs should be configured as per best practices to carry any Layer 3 traffic between the them.

The overlay interface will not come up until you configure a multicast group address and the site-VLAN has at least an active port on the OTV edge device.

Support for loopback interfaces as OTV Join interfaces is planned for 6.2(2) and later code releases.OTV ConfigurationStrong Recommendations and Key Notes 2013 Cisco and/or its affiliates. All rights reserved.#32FHRP Filtering Note: It is important to stress how this outbound path (server to client) optimization functionality should be deployed in conjunction with an equivalent one optimizing inbound traffic (client to server) flows to avoid asymmetric traffic behavior (this would be highly undesirable especially in deployments leveraging stateful services across data centers).White Paper discussing inbound traffic optimization solutions :: http://www.cisco.com/en/US/docs/solutions/Enterprise/Data_Center/DCI/4.0/EMC/EMC.pdf

It is important to note how OTV support requires the use of the new Transport Services (TRS) license. Depending on the specifics of the OTV deployment, the Advanced License may be required as well to provide Virtual Device Contexts (VDCs) support.

Before configuring OTV you should review and implement Cisco recommended STP best practices at each site. OTV is independent from STP but it greatly benefits from a stable and robust Layer 2 topology.

If the data centers are OTV multi-homed, it is a recommended best practice to bring the Overlay up in single-homed configuration first, by enabling OTV on a single edge device at each site. After the OTV connection has been tested in as single-homed, then enable the functionality on the other edge devices of each site.

OTV currently enforces switch-virtual-interface (SVI) separation for the VLANs being extended across the OTV link, meaning that OTV is usually in its own VDC. With the VDC license on the Cisco Nexus 7000 you have the flexibility to have SVIs in other VDCs and have a dedicated VDC for OTV functions.

Configure the join interface and all Layer 3 interfaces that face the IP core between the OTV edge devices with the highest maximum transmission unit (MTU) size supported by the IP core. OTV sets the Don't Fragment (DF) bit in the IP header for all OTV control and data packets so the core cannot fragment these packets.

OTV ConfigurationStrong Recommendations and Key Notes 2013 Cisco and/or its affiliates. All rights reserved.#33With NX-OS 6.1 and earlier: Only one join interface can be specified per overlay; two methods are availableConfigure a single join-interface, which is shared across multiple overlaysConfigure a different join interface for each overlay, which increases the OTV reliability

For a higher resiliency, you can use a port-channel, but it is not mandatory. There are no requirements for 1 Gigabit-Ethernet versus 10 Gigabit-Ethernet or dedicated versus shared mode.

The transport network must support PIM sparse mode (ASM) or PIM-Bidir multicast traffic.

OTV is compatible with a transport network configured only for IPv4. IPv6 is not supported.

Do not enable PIM on the join-interface.

Do not configure OTV on an F-series module.

Ensure the site identifier is configured and is the same for all edge devices on a site. OTV brings down all overlays when a mismatched site identifier is detected from a neighbor edge device and generates a system message.

Mixing the Nexus 7000 and the ASR 1000 devices for OTV is not supported at this time when the devices will be placed within the same site. However, using Cisco Nexus 7000s in one site and Cisco ASR 1000s at another site for OTV is fully supported. For this scenario, please keep the separate scalability numbers in mind for the two different devices, because you will have to account for the lowest common denominator.

Starting in NX-OS 5.2, the site-id command was introduced as a way to harden multihoming for OTV. It is a configurable option that must be the same for devices within the same data center and different between any devices that are in different data centers. It specifies which site a particular OTV device is in so that two OTV devices in different sites cannot join each other as a multihomed site. This command is now mandatory.OTV ConfigurationStrong Recommendations and Key Notes 2013 Cisco and/or its affiliates. All rights reserved.#34Using Virtual Port Channels (vPCs) and OTV together provides an extra layer of resiliency and is thus recommended as a best practice.

OTV & FabricPath: Because OTV encapsulation is done on M-series modules, OTV cannot read FabricPath packets. Because of this restriction, terminating FabricPath and reverting to Classical Ethernet where the OTV VDC resides is necessary. In addition, when running FabricPath in your network, we highly recommend that you use the spanning-tree domain command on all devices that are participating in these VLANs. This command speeds up convergence times greatly.

OTV ConfigurationStrong Recommendations and Key Notes 2013 Cisco and/or its affiliates. All rights reserved.#3542 Bytes overhead to the packet IP MTU size

(Outer IP Header + OTV Shim) (Original L2 Header without the 802.1Q header)802.1Q header is removed and the VLAN field copied over to the OTV shim headerOuter OTV shim header contains VLAN, overlay ID number, and an external IP headerConsider Jumbo MTU Sizing along the path between the source and destination endpoints to account for the extra 42 bytesOTV ConfigurationOTV Encapsulation :: MAC in IP 20B + 8B + 14B* = 42 Bytes of total overhead 6B6B2B20B8BDMACSMACEtherTypeIP HeaderPayload4BCRCOTV Shim802.1QDMACSMACEtherType802.1QVLAN ID, Overlay #14B*Original L2 FrameL2 Header802.1Q header removed* The 4 Bytes of the 802.1Q header have already been removedVLAN 2013 Cisco and/or its affiliates. All rights reserved.#36OTV ConfigurationHow OTV Works :: Inter-Site Packet Flow (OTV Data Plane)

MAC TableVLANMACIF10MAC 1Eth 110MAC 2IP B10 MAC 3Eth 3Assumption :: New MACs where learned in the VLANs that are OTV extended on the internal interfaces; an OTV update message was sent and replicated across the transport and delivered to all remote OTV Edge devices; those MACs learned through OTV are then imported in the MAC address tables of the OTV Edge Devices. Step 1 :: The Layer 2 frame is received at the aggregation layer or OTV Edge Device. A traditional Layer 2 lookup is performed, the MAC for Host Bs information in the MAC table does not point to a local Ethernet interface (as you would see in intra-site communication); but to the IP address of the remote OTV Edge Device that advertised that MACs reachability information. Step 2 :: The OTV Edge Device encapsulates the original Layer 2 Frame; with is the source IP of the outer header of the local Join interface & the destination IP which is the IP address of the remote Edge Device Join interface.Step 3 :: The OTV encapsulated frame (a regular unicast IP packet) is carried across the transport infrastructure and delivered to the remote OTV Edge Device. Step 4 :: The remote OTV Edge Device decapsulates the frame exposing the original Layer 2 packet. Step 5 :: The OTV Edge Device performs another Layer 2 lookup on the original Ethernet frame and discovers that it is reachable through a physical interface, which means it is a MAC address local to the site. Step 6 :: The frame is then delivered to the MAC destination of Host BMAC 1 MAC 2

IP A IP BMAC 1 MAC 2MAC TableVLANMACIF10MAC 1IP A10MAC 2Eth 210 MAC 3IP A

WEST DCEAST DCIP A IP BMAC 1 MAC 2MAC 1 MAC 2Layer 2 LookupLayer 2 LookupEncapDecapAnimation 2013 Cisco and/or its affiliates. All rights reserved.#37External (public)

OTV Best Practices Guidehttp://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9402/guide_c07-728315.pdf

OTV Technology Introduction and Deployment Considerationshttp://www.cisco.com/en/US/docs/solutions/Enterprise/Data_Center/DCI/whitepaper/DCI_1.html

Using OTV to Extend Layer 2 between Two Data Centershttp://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9402/white_paper_c11-644634.html

Nexus 7000 NX-OS OTV Configuration Guideshttp://www.cisco.com/en/US/docs/switches/datacenter/sw/nx-os/OTV/config_guide/b_Cisco_Nexus_7000_Series_NX-OS_OTV_Configuration_Guide.html

Cisco Nexus 7000 NX-OS Verified Scalability Guide (OTV Limits) http://www.cisco.com/en/US/docs/switches/datacenter/sw/verified_scalability/b_Cisco_Nexus_7000_Series_NX-OS_Verified_Scalability_Guide.html#reference_18192F87114B45D9A40A41A0DEF3F74D

Cisco Live 365 (sign up & search session catalog for OTV)https://ciscolive365.com/ BRKDCT 3103 :: Advance OTV Configure, Verify and Troubleshoot OTV in Your Network; Andy Gossett (CSE)OTV ConfigurationAdditional Resources & Further ReadingGreat External Resources 2013 Cisco and/or its affiliates. All rights reserved.#38Quick Start Guide :: Virtual Port Channel (vPC)https://communities.cisco.com/docs/DOC-35728

Quick Start Guide :: FabricPathhttps://communities.cisco.com/docs/DOC-35725l

OTV ConfigurationAdditional Resources & Further Reading 2013 Cisco and/or its affiliates. All rights reserved.#39 2013 Cisco and/or its affiliates. All rights reserved.#