This document describes how to configure Cisco Nexus 7000 Series switches so that they can be used with the Cisco Aggregated Services Router (ASR) in order to deploy Overlay Transport Virtualization (OTV) Layer 2 (L2) Data Center Interconnect technologies.
Cisco recommends that you have knowledge of OTV configurations for both the Nexus and ASR platforms.
The information in this document is based on these hardware and software versions:
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
Use the information in this section in order to configure the Nexus 7000 Series switch.
The example that is provided in this document uses this topology:
This section provides the configurations for the Nexus and ASR devices.
N7K-1-OTV# show run otv
!Command: show running-config otv
!Time: Tue Dec 14 21:12:57 2010
version 6.2(12)
feature otv
otv site-vlan 3000
interface Overlay1
otv join-interface Ethernet1/18
otv extend-vlan 2001
otv adjacency-server unicast-only
no shutdown
otv-isis default
otv site-identifier 0x2
N7K-1-OTV#
N7K-2-OTV# show run otv
!Command: show running-config otv
!Time: Tue Dec 14 21:22:20 2010
version 6.2(12)
feature otv
otv site-vlan 3001
interface Overlay1
otv join-interface Ethernet1/40
otv extend-vlan 2001
otv use-adjacency-server 10.1.1.2 unicast-only
otv adjacency-server unicast-only
no shutdown
otv-isis default
otv site-identifier 0x3
N7K-2-OTV#
ASR-OTV#show run
hostname ASR-OTV
!
otv site bridge-domain 1
!
otv site-identifier 0000.0000.0001
multilink bundle-name authenticated
!
interface Overlay1
no ip address
otv join-interface GigabitEthernet0/0/5
otv use-adjacency-server 10.1.1.2 unicast-only
otv adjacency-server unicast-only
service instance 2001 ethernet
encapsulation dot1q 2001
bridge-domain 2001
!
!
interface GigabitEthernet0/0/5
description ****OTV Join interface****
mtu 9216
ip address 10.1.1.1 255.255.255.0
shutdown
negotiation auto
cdp enable
!
interface GigabitEthernet0/0/6
no ip address
negotiation auto
service instance 1 ethernet
encapsulation untagged
bridge-domain 1
!
service instance 2001 ethernet
encapsulation dot1q 2001
bridge-domain 2001
!
ASR-OTV#
With the previous configurations in place, OTV adjacency should come up on all of the devices; however, you might observe that the OTV routes/ Media Access Control (MAC) addresses are only exchanged between Site 2 (N7K1) and Site 3 (N7K2). Examples are provided in the sections that follow.
N7K-1-OTV# show otv adjacency
Overlay Adjacency database
Overlay-Interface Overlay1 :
Hostname System-ID Dest Addr Up Time State
N7K-2-OTV 002a.6ae7.d442 10.1.1.3 1w4d UP
ASR-OTV 88f0.774a.2800 10.1.1.1 00:00:22 UP
N7K-2-OTV# show otv adjacency
Overlay Adjacency database
Overlay-Interface Overlay1 :
Hostname System-ID Dest Addr Up Time State
N7K-1-OTV 002a.6ae7.d441 10.1.1.2 1w4d UP
ASR-OTV 88f0.774a.2800 10.1.1.1 00:00:20 UP
ASR-OTV#show otv adjacency
Overlay Adjacency Database for overlay 1
Hostname System-ID Dest Addr Site-ID Up Time State
N7K-2-OTV 002a.6ae7.d442 10.1.1.3 0000.0000.0003 00:00:13 UP
N7K-1-OTV 002a.6ae7.d441 10.1.1.2 0000.0000.0002 00:00:19 UP
In the situation that is described in the previous sections (even if it includes only one Nexus switch), you begin to observe tracebacks and Invalid Vlan Range error messages on the ASR:
*Apr 2 17:21:33.056: %CLNS-3-VLANRANGEERR: (Overlay1): invalid vlan range received,
begin 131137536, end 131137536, step 1
-Traceback= 1#4b5dcf00e7618154330c28bbb7d4cf9c :7F681D4E7000+BD95181
:7F681D4E7000+BD95C59 :7F681D4E7000+BD94D0D :7F681D4E7000+8703A8A
:7F681D4E7000+86CB1B9 :7F681D4E7000+8705E11 :7F681D4E7000+87052C8
:7F681D4E7000+86F7EDF :7F681D4E7000+86F79DA :7F681D4E7000+86F794B
:7F681D4E7000+86DC3FF :7F681D4E7000+86FF620
The adjacencies remain up, but no routes are exchanged and the hosts cannot ping each other across the OTV. This occurs for all of the hosts between Site 1 and Site 2, as well as Site 1 and Site 3.
Cisco bug ID CSCuo44890 introduced a new CLI command (interop-enable) in the Nexus 7000 Series switch Versions 6.2(12) and later, which is required to be configured in order to ensure that the routes are exchanged between the sites.
Complete these steps in order to resolve the interoperability issue:
Here is an example:
N7K-1-OTV(config)# interface Overlay 1
N7K-1-OTV(config-if-overlay)# shut
N7K-2-OTV(config)# interface Overlay 1
N7K-2-OTV(config-if-overlay)# shut
N7K-1-OTV(config-if-overlay)# otv-isis default
N7K-1-OTV(config-router)# interop-enable
N7K-1-OTV(config-router)# end
N7K-2-OTV(config-if-overlay)# otv-isis default
N7K-2-OTV(config-router)# interop-enable
N7K-2-OTV(config-router)# end
N7K-1-OTV(config)# interface Overlay 1
N7K-1-OTV(config-if-overlay)#no shut
N7K-2-OTV(config)# interface Overlay 1
N7K-2-OTV(config-if-overlay)#no shut
You should now see route exchanges, and the hosts should be reachable across the OTV.
Revision | Publish Date | Comments |
---|---|---|
1.0 |
17-Apr-2015 |
Initial Release |