Core issue
The %CSM_SLB-4-TOPOLOGY error message occurs if the Content Switching Module (CSM) detects a bridge loop in the network.
The full error message looks similar to this:
%CSM_SLB-4-TOPOLOGY: Module 6 warning: ARP frame from
10.208.136.6 received on VLAN 234
Resolution
In order to resolve this issue, check the bridging device and the bridge-mode configurations of multiple CSMs located in the network.
Note: When a CSM is out of service, the module still replies to Address Resolution Protocol (ARP) requests but not to pings.
