Uplink adapters missing or disappear from vDS after a host reboot or upgrade

Products

• VMware vSphere ESXi

Issue/Introduction

In some cases, network adapters can unexpectedly become unassigned from uplinks on a virtual distributed switch (vDS) after an ESXi host is restarted or upgraded.

This can be exhibited with the following error seen in vSphere Client:

"No physical network adapters on this host are connected to the distributed switch. Virtual machines connected to the distributed switch which are running on this host might have network connectivity issues. To resolve these issues, connect at least one physical network adapter to the distributed switch."

In the topology view, one or more uplinks on the right side of the diagram indicate "(0 NIC Adapters)" where network adapters were expected to appear.

Resolution

If the host has lost connection to the vCenter server, connection must be restored using the DCUI or using the command line terminal using the steps in KB article vCenter network connectivity lost - Recover vCenter network when connected to a Distributed Switch

Once the host is connected to the vCenter server, use the vSphere Client to assign physical adapters using the Manage Physical Adapters option in Virtual switches or Add and Manage Hosts... in the network view.

Restart the host to ensure that the updated configuration has been saved correctly.