Peers sessions state is "Concat Path Down"; expect to be up but is down

Products

• VMware NSX

Issue/Introduction

Description about the error "peers sessions state is "Concat Path Down"; is expect to be up"

Symptoms:

• The output for the command "get diagnosis config" throws up the "Concat path down" error

sa-nsxedge-02> get diagnosis config

Passed:
    Manager, Controller, Nsxa-state, Nsxa-lrouter, Nsxa-service-router, NestDB
Failed:
    Nsxa-edge-cluster: peers sessions state is "Concat Path Down"; expect to be up

• The health status , Tunnel status in the UI shows up fine. 
• No impact on the Dataplane

Cause

The above error is seen when no routing (BGP) or Uplink is configured on the T0SR edge. It's usually seen on the edge cluster which is used primarily for T1.

If there is no T0 gateway or uplink then the above message is safe to ignore.

If there is a T0 gateway present and BGP or any other routing protocol is configured to connect the edge to the north router then the above message "Concat Path Down" represents that the edge has lost all the BGP/OSPF (northbound) sessions to the north router.

Resolution

This error is safe to ignore, in case we are not using the edge cluster for T0 BGP routing purposes or while just the T1 services are used.

Workaround:
N/A

Additional Information

Impact/Risks:
There is no impact