BGP Peer Monitoring for High Availability


In Legacy HA configuration, it is recommended for SE failover to happen when the BGP peers are inaccessible from Active SE. BGP peer monitoring is available by default on NSX Advanced Load Balancer. Starting with NSX Advanced Load Balancer version 21.1.3, failover on Legacy HA SE groups based on BGP peer monitoring is introduced.

BGP Peer Monitoring for Failover on Legacy HA

The SE agent periodically queries the bgpd an detects the peer state.
If the peer state changes, it will raise and event.
BGP peers are configured in the VRF.

Not all peers may be applicable on a particular SE. Only those peers with subnet matching any of the interfaces in the SE will be applicable on the SE.

Note: Peers in this article refer only to those BGP peers having matching interfaces on the SE.

Configuring BGP Peer Monitor Failover

Starting with NSX Advanced Load Balancer, BGP Peer monitor failover can be configured for a service engine via the CLI as shown below:

[admin:123-ctlr3]: > configure serviceenginegroup Default-Group               
[admin:123-ctlr3]: serviceenginegroup> bgp_peer_monitor_failover_enabled
Overwriting the previously entered value for bgp_peer_monitor_failover_enabled
[admin:123-ctlr3]: serviceenginegroup> save

Criteria for BGP Peer Monitoring

A peer monitor looks if the following conditions are met:

  • If peers with advertise_vip set are present, at least one such peer should be in the UP state.

  • If peers with advertise_snat_ip set are present, at least 1 such peer should be in the UP state.

For the peer monitor to mark the status as UP, both the conditions mentioned above have to be met. If not, the peer monitor marks the status as DOWN.

BGP Peer Monitoring in a Multiple VRF Scenario

In a multi-VRF scenario, each of the VRFs should satisfy the conditions for the SE’s peer monitor to mark the status as UP.
Immediately after a VRF configuration, BGP peer monitor will wait for two cycles of peer monitor queries before the peer monitor status is updated.

Document Revision History

Date Change Summary
December 20, 2021 Published the Feature KB for BGP Peer Monitoring