N7K upgrade process

[MatthewW98]

We are in the process of upgrading a VPC pair of N7K's and have one upgraded and moving on to the second. We are trying to isolate the second switch to upgrade it, and part of that would be shutting down the peer-link and KA. I can't find an official document that says if your supposed shutdown the peer-link and peer-keepalive or not and then upgrade the software. I have seen people do it both ways, but I think it's best to leave them up and just let the switchover happen itself, correct?

[Mark Elsen]

  - @MatthewW98     Checkout : https://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/nx-os/tech_note/vpc_upgrade.html
                                 It's indeed important to have sufficient knowledge before starting the upgrade(s)

  M.

[MatthewW98]

I have seen that document, so I will provide some more context on the current plan. The previously upgraded switch is now operating as primary, operational secondary (switch 1), and the switch we need to upgrade is secondary, operational primary (switch 2), which is expected and okay. From what I understand and have seen in labs though is if we just shut down the peer-link right now switch 1 will suspend all it vlans which is why I am hesitant to shut them down at all. 

The plan is to lower the priority on switch 1 and use "vpc role preempt" to make it the primary and then shut down the peer-link and KA. From my labs, this will work, but I have found on forums that it is best not to touch the priority and just let vpc fail-over when switch 2 reboots.

[Mark Elsen]

  - @MatthewW98             >.... but I have found on forums
                              Usually these devices play a central role and or in my opinion , it's  best to confirm
                              intended procedure for instance with a technical person from  a local reseller.
                              Or have the final procedure confirmed by a TAC case ,  (request)

   M.