There are certain situations when temporarily disabling network rollback might be a good idea, notice the use of the word temporarily as it’s not something you would want to leave disabled.
Let’s say you need to change the VLAN configuration on a network port which is used for vSphere management traffic from an access port to a trunk port. Before doing this you would need to change the vDS portgroup to tag the management traffic VLAN, however in doing this the host would lose management network access until the correct configuration was applied on the switch port.
The vDS would detect this change and attempt to rollback the configuration to untagged, obviously we don’t want this to happen in this instance so VMware allow us to disable this rollback feature.
We can do this by configuring the following settings.
- In the vSphere Web Client, navigate to a vCenter Server Instance.
- On the Manage tab, click Settings.
- Select Advanced Settings and click Edit.
- Select the config.vpxd.network.rollback key, and change the value to false. If the key is not present, you can add it and set the value to false.
- Click OK.
- Restart the vCenter Server to apply the changes.
Remember to revert the change once you are finished.