T0 Gateway in a Failed state with error FRR config failed:: ROUTING_CONFIG_ERROR (-1)

Products

• VMware NSX

Issue/Introduction

• The T0 Gateway throws below error on NSX UI with a Failed state:
  FRR config failed:: ROUTING_CONFIG_ERROR (-1)




• Below logs can be observed in NSX manager:
  
  2025-07-28T10:21:02.914Z nsx-mngr-01.corp.local NSX 88088 SYSTEM [nsx@6876 comp="nsx-manager" level="INFO" subcomp="manager"] Returning current realization status 'Status = 'ERROR', Message = ''2' transport nodes have reported errors.', TNs = '[TN = 'xxxxxx-xxxx-xxxx-xxxxxx', Status = 'ERROR', Message = '', Errors = '[Error Code = '6100', Error Message = 'FRR config failed:: ROUTING_CONFIG_ERROR (-1)', Affected Entities = '[]'.]'., TN = 'xxxxxx--xxxx-xxxx-xxxxxx', Status = 'ERROR', Message = '', Errors = '[Error Code = '6100', Error Message = 'FRR config failed:: ROUTING_CONFIG_ERROR (-1)', Affected Entities = '[]'.]'.]', Pending Changes = '[]'.' for entity 'LogicalRouter/xxxxxxx-xxxx-xxxx-xxxx-xxxxxxx'.
  
  
  

Environment

VMware NSX

Cause

There is a route map configured on the T0 attached to the BGP neighbor, with 2 community lists present in the match criteria with "Deny" action as below:

.
The edge node rejects a route-map sequence configured with a deny action that has more than one community list attached to its match criteria, and thus, changes into a Failed state.

Resolution

This is an unsupported configuration in NSX from version 4.x onwards: Release Notes:Issue 2898020
The Failed state of T0 gateway due to this configuration issue does not cause any operation or datapath impacts.