vCenter network connectivity lost after datastore unmapping and VDS configuration

Products

• VMware vCenter Server

Issue/Introduction

vCenter Server loses network connectivity and becomes inaccessible via the vSphere UI and VAMI. This typically occurs after an unplanned storage event (e.g., datastore unmapping) or if the vCenter VM is registered on a different host while connected to a Distributed Switch (vDS) with static port bindings. Because vCenter is offline, it cannot provide the necessary port bindings to its own virtual machine.

Symptoms:

• • vCenter vSphere Client and VAMI UI are inaccessible.
  • vCenter appliance cannot ping its gateway or other local IPs.
  • Unable to reconfigure the vCenter network adapter via the ESXi host UI (error: "Addition or reconfiguration of network adapters attached to non-ephemeral distributed virtual port groups is not supported").

Environment

VMware vCenter Server 7.x, 8.x 9.x

Cause

When vCenter is connected to a Distributed Switch using static (non-ephemeral) port groups, it manages its own network connectivity. If vCenter goes offline, the management of those ports is lost. If the VM is moved or restarted, it cannot re-attach to the vDS because vCenter is unavailable to assign a port

Resolution

To restore connectivity, you must temporarily migrate the vCenter VM to a Standard Switch (vSS):

1. 1. Identify a free vmnic: Use the ESXi command line (esxcli network vswitch dvs vmware list) to identify a vmnic currently attached to the vDS.
   2. Remove vmnic from vDS: Remove one vmnic from the vDS to make it available for a standard switch using esxcfg-vswitch -Q <vmnic> -V <PortID> <vDSName>.
   3. Create a temporary Standard Switch:
      • Add a standard switch: esxcli network vswitch standard add --vswitch-name=####.
      • Add a port group: esxcli network vswitch standard portgroup add --portgroup-name=#### --vswitch-name=####.
      • Assign the vmnic: esxcli network vswitch standard uplink add --uplink-name=<vmnic#> --vswitch-name=####.
      • Set the correct VLAN ID if necessary: esxcli network vswitch standard portgroup set --portgroup-name=#### --vlan-id <VLAN_ID>.
   4. Migrate vCenter to vSS: Using the ESXi Host Client, edit the vCenter VM settings and change its network adapter to use ####.
   5. Revert to vDS: Once vCenter is accessible, use the "Add and Manage Hosts" wizard in the vSphere Client to migrate the vCenter VM and the vmnic back to the original Distributed Switch.
   6. Cleanup: Delete the temporary Standard Switch.

Additional Information

vCenter network connectivity lost - Recover vCenter network when connected to a Distributed Switch