Tier 1 connected route missing from Tier 0 route table on Active Edge which is present on the Standby Edge

Products

• VMware NSX

Issue/Introduction

• You may have recently rebooted or upgraded an NSX edge node.
• A T1C route is not present in the T0 routing table in the active T0 edge
• The following messages may be seen in /var/log/frr/frr.log and also in /var/log/syslog

2025/02/19 17:13:40.190834 ZEBRA: 0:###.###.###.###/## doesn't exist in rib
2025/02/19 17:13:53.299993 OSPF: [EC #########] INTERFACE_STATE: Cannot find IF downlink-<id> in VRF 0
2025/02/19 17:14:05.404121 STATIC: Static Route using downlink-<id> interface not installed because the interface does not exist in specified vrf

Environment

VMware NSX 
VMware NSX-T Data Center

Cause

Routing controller reads interface kernel notifications via netlink socket. During edge reboot, netlink notifications might get dropped/missed. This leads to missed configuration on the interfaces in comparison to the kernel.

Resolution

This is a known issue impacting VMware NSX.

Workaround:
To recover the missing IPv4/IPv6 addresses, the interfaces can be rescanned using the below command in the edge node CLI as admin user:

Edge> get logical-routers
Edge> vrf <vrf_id of SERVICE_ROUTER_TIER0>
Edge(tier0_sr)> set debug
Edge(tier0_sr)> start rescan interfaces
Edge(tier0_sr)> exit
 
NOTE: For VMware NSX versions prior to 4.1.2, please do not use the workaround on EVPN enabled setups.

Additional Information

Other symptoms relative to this issue are detailed in the following kb:
https://knowledge.broadcom.com/external/article/377814/vmware-nsx-edge-routing-fails-due-to-the.html

For additional information related to specific scenarios impacting BGP neighbors failing to establish due to IPv4/IPv6 addresses missing on NSX-T edge node interfaces, please refer the following kb:
https://knowledge.broadcom.com/external/article?articleNumber=322523