vPC issue

[Mustapha Bassim]

hello

we have two nexus 9138 switches that are connected to servers using VPC configuration when I preferred to upgrade for one of them the servers indicated the interfaces went down and no network connection appears while the second switch is up . this scenario not appear when we disconnect one of interfaces in swithces since the VPC with servers is up from second one so please we need advise for that

Bests

[MHM Cisco World]

check the server NIC  teaming. 

[Mustapha Bassim]

thnx for reply , the nic team look fine since when disconnect one of interface the process working fine

[MHM Cisco World]

Understand the sequence is so important to understand the problem and how we can solve it, 

from cisco doc. about auto-recovery,

""Since vPC peer-keepalive is still on, it detects dual-active detection. The vPC secondary S2 turns off all its local vPCs.""

this normal vPC behave where when the VPC peer-link is down but the peer-keepalive is still ON, in this case the secondary is tunr off ALL its local vPC and hence you loss connectivity to Server.
https://www.cisco.com/c/en/us/support/docs/switches/nexus-7000-series-switches/116187-configure-vpc-00.html

please read the Doc. and confirm that this what you face.