Networking Operations Fail After Reinstalling an ESXi Host Enrolled in a vSphere Distributed Switch (VDS)

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms

After reinstalling ESXi on a host or replacing a failed server with a new installation using the same IP address/hostname, you experience the following symptoms:

• Networking configuration operations fail on the reinstalled host.
• Attempts to migrate virtual machine or VMkernel traffic from a vSphere Standard Switch (VSS) to a vSphere Distributed Switch (VDS) fail.
• The vCenter Server indicates configuration sync errors or status mismatches for the specific host within the VDS inventory.

Context

This issue typically occurs if the original ESXi host experienced a corruption or hardware failure and was deleted or reinstalled without first being gracefully removed from the VDS.

Environment

• VMware ESXi
• VMware vCenter Server

Cause

When an ESXi host is reinstalled or replaced, its local VDS runtime configuration is lost. However, if the host was not gracefully removed from the VDS inventory within vCenter Server prior to the reinstallation, vCenter Server still considers the host a member of the switch.

Upon reconnection, vCenter Server attempts to automatically push the existing VDS configuration back to the host. This process fails if there is a resource conflict—most commonly when the physical network adapters (vmnic0, vmnic1, etc.) required by the VDS configuration are currently allocated to the default Standard Switch (vSwitch0) created during the fresh ESXi installation. Because the host lacks the VDS configuration, subsequent network migration tasks fail.

Resolution

To resolve this issue, the host's stale registration must be cleared from the Distributed Switch configuration in vCenter Server, and the host must be cleanly re-added.

Step 1: Remove the Host from the VDS

1. Log in to the vSphere Client.
2. Navigate to the Networking view (Globe icon).
3. Expand your Data Center and locate the affected vSphere Distributed Switch.
4. Right-click the VDS and select Add and Manage Hosts.
5. Select the Remove hosts radio button and click Next.
6. Select the checkbox next to the affected reinstalled ESXi host and click Next.
7. Review the impact analysis and click Finish.

Step 2: Re-add the Host to the VDS

1. Right-click the same Distributed Switch and select Add and Manage Hosts.
2. Select the Add hosts radio button and click Next.
3. Click New hosts, select the reinstalled ESXi host, click OK, and then click Next.
4. Follow the wizard to appropriately assign physical network adapters (vmnics) and migrate VMkernel ports or virtual machine networking as originally intended.
5. Click Finish.

Once the host is cleanly re-added, retry your original network migration or configuration operations.

Additional Information

vSphere Distributed Switch (VDS) 構成済みの ESXi ホストを再インストールするとネットワーク操作が失敗する