Enabling CGMP and IGMP Snooping

Enabling CGMP and IGMP Snooping
When hosts connect to a router via a Catalyst switch, either CGMP or IGMP Snooping can be
used to enable the switch to learn appropriate information. Catalysts run both so they can manage
multicast membership reports from the router accordingly and so they can manage multicast
ports on the switch. The router is the device that listens for the IGMP membership report;
it then tells the switch which port needs to be activated. CGMP or IGMP Snooping must be activated
on both the router and the switch.