NSX Edge Transport Node Tunnels Down Between Edge Nodes

Products

• VMware NSX

Issue/Introduction

• After a new deployment, TEP (Tunnel Endpoint) tunnels between NSX Edge nodes are observed to be in a DOWN state.

• This prevents overlay traffic communication between the edge transport nodes.

Symptoms:

• The NSX UI Edge Transport Nodes page shows all tunnel statuses as DOWN:
  

Environment

• Product: VMware NSX 9.0.1.0 (as reported in case data)

• Configuration: Edge Transport Nodes utilizing an Uplink Profile for TEP communication.

Cause

The uplink profile assigned to the Edge nodes is configured with an incorrect Transport VLAN. In this specific scenario, the profile was using the default VLAN 0 instead of the required VLAN. This misconfiguration prevents the Edge nodes from correctly tagging TEP traffic, resulting in the physical switches dropping the untagged or incorrectly tagged packets.

Resolution

To resolve the tunnel down state, update the Uplink Profile with the correct Transport VLAN:

1. Log in to the NSX Manager UI.

2. Navigate to System > Fabric > Profiles.

3. Locate the Uplink Profile assigned to the affected Edge Transport Nodes.

4. Click the three dots (ellipsis) next to the profile and select Edit.

5. Locate the Transport VLAN field.

6. Update the value to the correct VLAN ID (e.g., 100).

7. Click Save.

Defining the correct transport VLAN ensures that the Edge nodes tag TEP traffic accurately, allowing the tunnels to successfully establish over the physical underlay network.

Additional Information

• Edge tunnels down alarm

• NSX Edge TEP networking options

• TEP tunnels are down between ESXi Transport Node and Edge Transport Node. (Alarm: Event type: Faulty TEP)

• Troubleshooting NSX TEP/BFD Tunnels between ESXi hosts and Edges