FWM-2-STM_LOOP_DETECT detected on switch, dynamic learning disabled(STP)

When FWM-2-STM_LOOP_DETECT is detected on the switch, dynamic learning is disabled.

Possible Cause

•MAC addresses are moving because of incorrect STP-port state convergence.

•MAC addresses are moving because the source of the data being physically moved across all switches while STP states are converged and in correct states.

Use the following commands to verify the STP port state across VLANS on the switches:

•show spanning-tree

•show spanning-tree vlan <id>

Solution

•Check for a correct STP convergence and for STP port states across all switches in the topography. Also confirm that there are no disputes or incorrect port states.

•If the source of the data frames, which are physically moving, is identified, then control the source to halt rapid and continuous moves.

•By default, dynamic learning is opened after 180 seconds. At that point, any STP disputes or inconsistencies should be resolved.