In order to identify OSI layer 2 reachability issues, an L2 algorithm is used to ping the MAC addresses of the other ports in the cluster that belong to the same broadcast domain. The L2 ping is perfo...In order to identify OSI layer 2 reachability issues, an L2 algorithm is used to ping the MAC addresses of the other ports in the cluster that belong to the same broadcast domain. The L2 ping is performed by sending Connectivity Fault Management (CFM) frames A port considers itself 'healthy' if it receives a CFM frame from any other port in its configured broadcast domain A port considers itself 'degraded' if it is receives no CFM frames from its configured broadcast domain