VLAN MTU healthcheck send the probing packet to unexpected VLAN

Products

• VMware vCenter Server

Issue/Introduction

A vDS health check shows VLAN 0 (as either "Supported" or "Not supported") when no portgroups are configured to use the native VLAN.

Checking the corresponding port property on the host using net-dvs -l, the `Untrunked VLAN` and `Untrunked MTU` are 0.

vCenter networking review reported Port ID "hlp-" with VLAN 0.

Cause

Restoring the vDS from the ESXi DCUI can lead to stale dvPorts (with VLAN 0) being created. In this way, the VLAN MTU health check will involve those ports.

Resolution

Currently, there is no resolution to the issue.

Please open a Broadcom Support case if you run into this issue, and mention this KB.

Workaround:

Create a new vDS and migrate the workload and vmnics from the old vDS to the new one, and delete the old vDS when everything is moved over.