vPC between Nexus and 3750X in stack

[PrakashMatuwani]

Hello,

Can someone please let me know if you have tried the following connectivity. Does it works fine?

- Each 3750X in stack will connect to both the Nexus switches in vPC . Attached is the connectivity diagram

Regards,

Prakash Matuwani

[Mark Malone]

Hi

Yes that's no problem , just on the switch end though it will be port-channel and on the Nexus side a VPC , as it stacked though do you really need that much cabling , just connect one link of the po to one switch and the 2nd to say the bottom switch so its across the stack to give redundancy

[PrakashMatuwani]

Hi Mark,

Thanks for your reply.

Yes, we have one connection between 3750 and Nexus as follows

first 3750X ---> first Nexus

second 3750X ---> second Nexus

Was just thinking if i can have more resiliency. 

Regards,

Prakash Matuwani

[Mark Malone]

Hi

yes understand resiliency is key to good setup ,you could also just add a couple of extra links to the 1 vpc rather than doubling up on vpcs on same switch , im just thinking if something does eventually go wrong it will be a lot easier to tshoot with 1 vpc than 2 coming off same stack but both ways should work for you , you would definitely want the pos cabled like the diagram too split across both nexus switches

[PrakashMatuwani]

Hi Mark,

I have one more question not completely related to this discussion.

Have you tried creating vPC KEEPALIVE link as L3 port-channel? 

I read many cisco documents and config guide to find the answer but everywhere the keepalive link is mentioned as a single connection. vPC peer link is in port-channel but not the keepalive.

Regards,

Prakash Matuwani

[Mark Malone · Accepted solution]

that's the way we have it built in po , both of them , peer-link in another po too

interface port-channel100
  description VPC Heartbeat
  logging event port link-status
  vrf member heartbeat
  ip address x.x.x.x/x

peer-keepalive destination x.x.x.x source x.x.x.x vrf heartbeat

100   Po100(RU)   Eth      NONE      Eth3/46(P)   Eth4/46(P)

[PrakashMatuwani]

Thanks for sharing the information.

Regards,

Prakash Matuwani