Description

In the JUNOS EVO device with dual routing-engine, if the routing-engine mastership changed due to switchover, SNMPv3 authentication failure may occur

Symptoms

SNMP v3 authentication failure might appear if you have a configuration of a shared IP address in the management interface with the configuration knob of master-only,
 

Solution

Authentication failures are occurring due to the change in SNMPv3 engine-id upon routing-engine switchover. Whenever there is a change in the SNMPv3 engine-id, you will need to reconfigure your SNMPv3 authentication parameters to ensure successful authentication.

As a workaround, and to avoid the change of SNMPv3 engine-id you will need to configure the SNMPv3 engine-id manually 

set snmp engine-id local <engine-id-value>

In the new JUNOS EVO releases (w/ fix of PR 1792360) , the engine-id is now calculated based on the configured mastership IP "master-only" under the management interface address. This will result in always having the same engine-id whenever there is a mastership switchover.

Modification History

2024-03-06 : Article Created