vSS to vDS Migration Fails With Network Configuration Disconnected Rollback Error

Products

• VMware vCenter Server

Issue/Introduction

When attempting to migrate VMware vSphere ESXi Management (VMK0), the vCenter Server VM, and the only physical uplink (VMNIC) from a vSphere Standard Switch (vSS) to a vSphere Distributed Switch (vDS), the operation fails. The task times out or returns the following error:

"An error occurred while communicating with the remote host. Network configuration change disconnected the host from vCenter Server and has been rolled back. Cause: A change in the network configuration disconnected the host from vCenter Server. The change has been rolled back."

Environment

VMware vSphere
VMware vCenter Server 

Cause

The issue occurs due to a momentary network interruption during the simultaneous migration of the host's management interface and the vCenter Server's network connection over a single physical uplink. Because vCenter relies on this uplink, the temporary loss of connectivity triggers the ESXi Network Rollback feature, reverting the configuration back to the vSS to prevent permanent isolation.

Resolution

Option 1: Multi-Host Cluster (Recommended)

1. Verify the vMotion network is correctly configured on the affected ESXi host.

2. Migrate the vCenter Server VM to a different ESXi host within the cluster using vSphere vMotion.

3. Migrate the original ESXi host's VMK0 interface and its physical uplink (VMNIC) to the vDS.

4. Once the host network migration is complete, the vCenter Server VM can be migrated back to the original host if desired.
   
   

Option 2: Single Standalone Host (Workaround) Prerequisite: Ensure the destination Distributed Port Group for the vCenter Server VM is configured with Ephemeral (no binding) port allocation. Static port binding requires vCenter to be online to allocate a port; Ephemeral binding allows the ESXi host to allocate the port independently during the network interruption.

1. Log into the vSphere Client and select the vCenter Server in the inventory.

2. Navigate to Configure > Settings > Advanced Settings.

3. Click Edit, filter for config.vpxd.network.rollback, and change the value from true to false.

4. Click Save.

5. Navigate to Networking, right-click the target vDS, and select Add and Manage Hosts.

6. Select Manage host networking and choose the ESXi host.

7. In the wizard, select all three options simultaneously: Manage physical adapters, Manage VMkernel adapters, and Migrate virtual machine networking.

8. Assign the single VMNIC to the vDS uplink, assign VMK0 to the management Distributed Port Group, and assign the vCenter Server VM to the Ephemeral Distributed Port Group.

9. Complete the wizard. (Note: The vSphere Client may temporarily lose connection. Refresh the browser after 1-2 minutes).

10. Re-enable Network Rollback by navigating back to vCenter Server Advanced Settings, editing the config.vpxd.network.rollback key, setting the value back to true, and clicking Save.

Additional Information

For multi-node deployments, ensure vCenter is gracefully moved prior to network migration to avoid modifying Advanced Settings.