Edge Node Tunnels Down in Version 9.1.0 Due to Missing VLAN Configuration

Products

• VMware NSX

Issue/Introduction

In a new environment setup using version 9.1.0:

• Edge nodes show all four tunnels in a down state.

• When multiple Edge VMs are moved to the same ESXi host, the tunnels establish successfully, but they fail to communicate across different hosts in the cluster.

Environment

NSX 9.1

Cause

The Edge node VMs are configured to use specific host uplinks and a designated VLAN. However, the necessary VLAN is missing from the backing NSX DVS. This configuration mismatch prevents the distributed switch from forwarding the tagged overlay traffic externally across the ESXi hosts in the cluster.

Resolution

To resolve this issue, you must configure the required VLAN on the backing virtual switch:

1. Verify the uplinks and VLAN ID currently configured on the Edge nodes. 

2. Configure the missing VLAN on the NSX DVS across the ESXi hosts in the cluster.

3. Verify that the Edge node tunnels come up successfully when the VMs are distributed across the ESXi hosts in the cluster.