When adding additional new TEPs to Bare Metal Edges, sometimes the new TEP experiences flapping and tunnel instability

Products

• VMware NSX

Issue/Introduction

• NSX is using Bare Metal Edges
• Multiple NSX Environments (NSX Managers) share the same Layer 2 network for TEPs
  • The same VLAN is in use for Overlay Network on all NSX Environments
  • TEPS may use the same subnet

Environment

VMware NSX

Cause

Each NSX Manager uses the same range of MAC addresses when assigning MACs to TEPs on Bare Metal Edges.

If a NEW TEP created in Environment 2 happens to be assigned the same MAC as a TEP in Environment 1, the TEPs will start flapping as the physical infrastructure will see the SAME MAC address on two different ports. This will affect any TEP attempting to communicate with the TEPs sharing the same MAC address.

Resolution

Workaround: Delete the newest TEP and create it again. This will deploy the TEP with a different MAC address.

To ADD an additional TEP to a Bare Metal Edge:

1. Log into the NSX interface.
2. Navigate to System → Fabric → Profiles → Uplink Profiles
3. Click Edit on the Uplink Profile in use by the Bare Metal Edges
4. Click the blue number beside Teamings
   
   
5. In the dialogue box that pops up, click Edit beside the active Teaming Policy
   
   
   
6. Ensure the Teaming Policy is Load Balance Source
7. Ensure at least 2 uplinks are in the Active Uplinks box
   
8. Click Add
9. Click Apply
10. Click Save
11. A new TEP will be created on the Bare Metal Edge.

To DELETE a TEP from an Edge that already has multiple, follow the procedure above but reduce the number of Active Uplinks.

See KB345804 for detailed steps involving multiple possible workarounds.

Additional Information

Enabling Multiple TEPs on Bare Metal Edges is often done to enable Multi-TEP High Availability.