Port Group Mismatch Across ESXi Hosts Results in Network Unavailability
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Port Group Mismatch Across ESXi Hosts Results in Network Unavailability

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Article ID: 431907

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Updated On:

Products

VMware vSphere ESXi

Issue/Introduction

In a VMware vSphere environment, virtual machines (VMs) may lose network connectivity or become unable to be assigned to a specific network backing when residing on a particular host in a cluster.

Symptoms:

  • A specific VLAN or Network Label is visible and functional on some hosts but missing on others.

  • Attempts to assign a VM to a port group fail with errors indicating the network backing is unavailable.

  • VMs migrated via vMotion to an inconsistent host lose network connectivity.

  • Error: "The network 'VLAN_NAME' is not available on host 'HOSTNAME'."

Environment

 

  • Product: VMware vSphere / ESXi

  • Versions: 6.x, 7.x, 8.x, 9.x

  • Component: vSphere Standard Switch (vSS)

 

Cause

The issue is caused by a configuration inconsistency across ESXi hosts. vSphere Standard Switches (vSS) are managed at the individual host level. Unlike vSphere Distributed Switches (VDS), Standard Switches do not automatically synchronize port group names or VLAN IDs across the cluster. If a port group is manually created on three hosts but omitted on the fourth, the fourth host will have no logical mapping for that network traffic.

Resolution

To resolve this issue, the missing port group must be manually created on the affected host(s) to match the configuration of the rest of the cluster.

  1. Log in to the vSphere Client.

  2. Navigate to the ESXi Host that is missing the network.

  3. Select the Configure tab.

  4. Under Networking, select Virtual switches.

  5. Click Add Networking.

  6. Select Virtual Machine Port Group for a Standard Switch and click Next.

  7. Select the target Standard Switch (e.g., vSwitch0) and click Next.

  8. In Connection settings, enter the Network Label exactly as it appears on the other hosts (case-sensitive).

  9. Enter the correct VLAN ID (e.g., 10).

  10. Review the settings and click Finish.

  11. Verify connectivity by assigning a VM to the newly created port group.

Workaround: Migrate VMs to a host where the port group is correctly configured until the local configuration on the affected host is remediated. To prevent future occurrences, migrate the cluster networking from Standard Switches to a Distributed Switch (VDS), which ensures configuration parity across all members of the Distributed Switch.

Additional Information

Reference doc: Create a Virtual Machine Port Group

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