Nexus 9000 OSPF adjacency over peer-link

[rafaelbianco]

Hello guys!

I have a pair of 9508 in a vPC domain. On 9508-1 we have a firewall (not vPC attached) that needs to form an OSPF adjacency with both 9508-1 and 9508-2 over a vpc VLAN. 

I know for a fact (already tested) that this works on N7Ks, but I don't know if that works with N9Ks. Please refer to the topology for a clearer picture...

Thanks!

[Ganesh Hariharan]

Hi ,

it will work , but would recommend to use dedicated l3 or l2 trunk for ospf packets in vac domain.

Have a look on the below link

http://www.cisco.com/c/en/us/support/docs/ip/ip-routing/118997-technote-nexus-00.html

Hope it helps..

-GI

[rafaelbianco]

Hello Ganesh!

Yep... It did work. Do you happen to know why this is not supported? Every document I can get says it's not supported but it doesn't say why it's not. And the thing is that it's working...

Seems to me that I could potentially be susceptible to a problem but I don't know what.

Thanks!

[Ganesh Hariharan]

Hi ,

Based on my research what i can say ...

Dynamic Routing over vPC feature enables L3 routing protocols such as OPSF to form adjacency with the two vPC peer chassis.

The equal routing cost matrices must be configured on applicable interface on each of the vPC peers, failure to do so can result in blocking the traffic. Asymmetric routing feature has to be implemented to address this issue and to configure Dynamic Routing over vPC.

Additionally, when Dynamic Routing over vPC is enabled a warning log message is printed.

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/7_x/nx-os/release/notes/72_nx-os_release_note.html

Hope it Helps..

-GI

[rafaelbianco]

Ganesh,

I think what the release notes is saying is forming L3 adjacency over a vPC link, as in a router dual attached to both nexus with vPC and forming the adjacency.

This is a new feature introduced on code v7. 

Thanks!

[Ganesh Hariharan]

Hi , It could be on recent release ..do you have ref document for further study.

-GI

[l33d5un1t3d]

A word of warning Dynamic routing over vPC is now support beyond 7.2, but on F-series modules only.

Dynamic Routing over vPC

Dynamic Routing over vPC feature is supported only on F2E and F3 series modules. This feature enables L3 routing protocols such as OPSF to form adjacency with the two vPC peer chassis. The equal routing cost matrices must be configured on applicable interface on each of the vPC peers, failure to do so can result in blocking the traffic. Asymmetric routing feature has to be implemented to address this issue and to configure Dynamic Routing over vPC. Additionally, when Dynamic Routing over vPC is enabled a warning log message is printed.