Troubleshooting BGP neighbor status shown as 'Administratively shut down' and doesn't come up even after toggling enable from NSXT GUI in manager mode

Products

• VMware NSX

Issue/Introduction

BGP neighbor status shows Administratively shut down and it doesn't come up even after toggling enable from NSXT GUI

BGP neighbor is ###.###.###.###, remote AS #####, local AS #####, external link  
 Administratively shut down  
  BGP version 4, remote router ID #.#.#.#, local router ID 10.###.###.###.###  
  BGP state = Idle  
  Last read ##:##:##, Last write never  
  Hold time is ###, keepalive interval is ## seconds  
  Configured hold time is 180, keepalive interval is ## seconds

Below syslogs may be observed on NSX edge 

xxxx-xx-xxTxx:xx:xx.xxxZ t0-<FQDN-EVM>.local NSX 1838 - [nsx@6876 comp="nsx-edge" s2comp="nsx-monitoring" entId="xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxxx" tid="xxxx" level="ERROR" eventState="On" eventFeatureName="routing" eventSev="error" eventType="bgp_down"] Context report: {"entity_id":"xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx","sr_id":"xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx","lr_id":"xxxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx","bgp_neighbor_ip":"xxx.xxx.xxx.xxx","failure_reason":"Edge is not ready"}

Environment

3.2.2.0.0.20737193

Cause

The cause of this issue could be that NSX edge doesn't come up properly after a reboot or application crash. Check the NSX edge logs or core dumps generated for the cause of the issue

Resolution

Below troubleshooting steps could be preformed on the NSX edge VM 

• Check the status of virtual interfaces and TEP IPs of Edge VMs & the ESXi host where the Edge VM is deployed.
• Check BGP neighbor is reachable from Tier0-SR of Edge VM
• Check if the issue gets resolved after reboot of Edge VM and reboot of ESXi hosts
• Migrate Edge VMs to another ESXi host and check if BGP with neighbors comes UP

Additional Information

Toggling Admin status can be performed from NSX GUI manager mode