Description

This article explains an issue where the MNHA cluster fails over from one node to another continuously.

Symptoms

You will notice that the active and backup roles for SRG1+ shift from node0 to node1 and vice versa continuously after every few minutes. This will cause traffic interruption as well. You can use below given command to monitor the cluster status:

user@srx>show chassis high-availability information 

Solution

When you configure BFD monitoring for upstream or downstream links in an MNHA setup, you may encounter situations where BFD sessions flap intermittently or randomly, which can trigger repeated cluster failovers.

You can use the following command to monitor BFD sessions:

user@srx> show bfd session

While troubleshooting BFD-related issues, ensure that the BFD timers are configured according to the recommendations provided in the following Juniper document: BFD-Based Probing.

 

Note: If BFD sessions continue to flap without a clear or identifiable cause, it is recommended to contact JTAC for assistance in diagnosing and resolving the root cause.

Modification History

2026-06-18 : Article Created