Dell POWEREDGE M1000E - Manual (Page 632)

610 Fabric OS Message Reference
53-1002749-01
MCAST_SS-1020
5
MCAST_SS-1020
Message List Error: <op> (<reason>) VLAN <vid> MAC <mac address> group <group address>.
Message Type LOG
Severity ERROR
Probable Cause Indicates that the multicast subsystem (MCAST_SS) has encountered an error during the List operation.
Recommended
Action
Restart the MCAST_SS daemon.