Mitigate traffic issues after a MAC change of a guest Virtual Machine VNIC

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:
To recover the guest Virtual Machine from traffic loss issues when the below mentioned sequence of events occur:

1. MAC address of the VNIC of a guest Virtual Machine is changed.
2. MAC change is then enabled on the portgroup to which the guest Virtual Machine connects.

Environment

VMware vSphere 7.0.x
VMware vSphere 6.7.x

Cause

When the MAC address of a guest Virtual Machine is enabled before "MAC address change" is enabled on a port group, the port gets blocked. When MAC address change is subsequently enabled on the portgroup, the port gets unblocked. However, the old MAC address filter (The old MAC the guest Virtual Machine was using) is still applied on the VNIC port.

Resolution

Currently there is no resolution to this issue.

Workaround:

To workaround the issue please re-enable the interface on the guest Virtual Machine.