Dynamic Routing Over VPC

[SharukhKhan5504]

Hello Guys,

I am confused in Routing with VPC , Lets say i am having 2 nexus , A&B in VPC and I had attached Router in vpc and i need to form ospf adjacency between both the nexus so whats issues i will face , from router point of view it should have 2 neighbour A&B , Router will send only 1 hello from its portchannel so how this hello will be going to both nexus , i read need to use peer gateway & layer 3 peer router feature but i seen 1 video from ine that when u do routing in vpc do peer-gateway exclude vlan xx , need to exclude vlan from peer gateway otherwise router need to send LSU to A and due to hash it sends to B , so B will consume that

[Deepak Kumar · Accepted solution]

Hi,

Dynamic routing over the VPC is possible but it depends on your network diagram, IOS Version, license and requirement, etc. 

Visit for basic details: https://indeni.com/blog/how-to-use-cisco-nexus-osfp-over-vpc-review-cisco-nexus-osfp-vpc-implementation-verification/

[SharukhKhan5504]

Hello

Thanks alot for the doc , i had a query , i did not use layer 3 peer router but from router it has 2 ospf nei which is both nexus nexus in vpc , now my ques is lets say when router needs to send dbd packet to A so its A and it hashes to B so B need to send to A so B will decrement TTL and can not send so my neighbourship needs to stuck in exstart/exchange so how its up without that feature , any 1 nei should be stuck in exstart/exchange , i i tested yesterady on 93180 it is up