The Cat6500 does not support CGMP client, meaning that the L2 switch cannot receive CGMP notices from a router running CGMP. However, the MSFC does support CGMP Server and can provide multicast information via CGMP to downstream switches that are not able to use IGMP Snooping natively. For example, the Cisco 2900 or 3500 series switches do not support IGMP Snooping and must use CGMP to restrict multicast sessions within a VLAN. The newer 2950 and 3550 switches support IGMP Snooping.
So, you should use IGMP Snooping on the Cat6500 switch and I would recommend still configuring the MSFC for CGMP on the VLAN interfaces and make sure to enable CGMP on any switches that don't support IGMP Snooping.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...