ESXi hosts not communicating via VPC peer link on Nexus 93180YC-EX

[c.walsh]

We have a pair of Nexus 93180YC-EX switches running NSOX version 9.3 (5) deployed in a vPC pair.

We have 3 ESXi hosts connected to these switches running version (6.7), hosts 1 & 3 connect to Nexus switch 2 & host 2 connects to Nexus switch 1.

We have HSRP running for the vlan between the 2 nexus switches over the vPC peer link successfully.

There are other vlans/connectivity working fine using vPC connections to both of the nexus switches.

Problem is connectivity between vm's, when the traffic has to cross the vPC peer link.

i.e. if a vm is deployed on host 1, it can communicate with vm's on host 3 (connected to the same nexus switch), but not a vm deployed on host 2 (connected to the other nexus switch in the vPC pair).

We cannot connect the hosts to both Nexus switches, due to limitations of nic cards.

The vPC is up on both switches, is there something i am missing?

thanks

Colin

[Christopher Hart]

Hi Colin,

To determine the root cause of this issue, we will need a few more details about the nature of your topology. Specifically:

1. Are the virtual machines that exhibit this network connectivity issue on the same VLAN, or different VLANs?
2. If the same VLAN, what specific VLAN is affected?
3. If different VLANs, what specific VLANs are affected?
4. Are all relevant VLANs trunked across the vPC Peer-Link on both switches?
5. Are the Nexus 93180YC-EX switches the gateway for all relevant VLANs, or only some VLANs?

Try to be as specific as possible when troubleshooting this issue - include details about VLANs, MAC addresses, IP addresses, interface names, switch hostnames, etc. when describing this issue.

Thank you!

-Christopher

[c.walsh]

Hi Christopher,

   I have been advised to remove all of the vPC configuration from the pair of cisco nexus switches & removed LACP from the DVSwitch & reconfigure to use Load balancing based on IP Hash. 

That has resolved the issue.

[Christopher Hart]

Hi Colin,

I am glad that you were able to find a solution to the issue, although it's unfortunate you had to remove vPC from your design completely to get it working.

Best wishes, and thank you!

-Christopher