===================================================================
@@ -47,6 +47,9 @@ UDP (0x0111) or IPoIB (0x0002) port spac
Basic usage is to start mckey -m multicast_address on a server system,
then run mckey -m multicast_address -s on a client system.
.P
+Unique SA assigned multicast GIDs can be retreived by invoking mckey
+with a zero MGID using the unmapped option, i.e -M ::0
+.P
Because this test maps RDMA resources to userspace, users must ensure
that they have available system resources and permissions. See the
libibverbs README file for additional details.