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Cisco Bug: CSCun99636 - Standby Supervisor Stuck on Reload in 4k VSS due to SNMP Server traps

Last Modified

May 03, 2019

Products (1)

  • Cisco IOS

Known Affected Releases


Description (partial)

In a 4500X VSS system running 03.05.XX, after a failover between the Active and Standby switches, the former active (now standby) supervisor engine will fail to join VSS on bootup due to a mismatched configuration between the two switches.

The mismatched configuration is triggered by the command "no snmp-server enable traps license usage error display", which will be displayed in the syslog after the standby initially tried to re-join the VSS.

Subsequent reloads of the standby member after the initial failure will display the the failure reason as a version mismatch, and not a command mismatch. 

The behavior is triggered by modifying SNMP server traps in such a way that "no snmp-server enable traps license" is entered into the configuration.

For example, issuing "snmp-server enable traps" followed by "no snmp-server enable traps" will trigger this behavior.
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