Symptom

After a switchover, Cat9500 Stackwise virtual with interface in the Active switch in admin shutdown shows constant incoming control traffic.

Conditions

* Cat9500 SVL deployment. Issue not seen in standalone. * Issue has been seen on 16.8.x and 16.9.x. * Interface "Status" led is in green color. * The "show interface" command shows the interface in Admin Down status but the "packets input" counter is constantly increasing. * The trigger for this behavior is a Stackwise failover, with the interface configured as port-channel member, in admin down state and with the SFP and fiber connected. * The behavior is triggered after 1 or 2 failovers and always in the SVL Active switch. Once the problem has been triggered, if a new failover is performed, the issue follows to the SVL Active switch. * The peer device in the other side of the link of the affected port and configure as port-channel member goes to Suspended mode. * A "no shut/shut" doesn't resolve the problem.

Workaround

* Reload of the entire SVL Stack.

Further Problem Description