Your switches can reduce the unnecessary flooding of IP multicast packets by limiting the transmission of these packets to groups of clients that request them. When clients (end stations) automatically join and leave groups that receive IP multicast traffic, your switches can dynamically change their forwarding behavior according to join and leave requests. To give you this control, your switches use either Cisco Group Management Protocol (CGMP) or Internet Group Management Protocol (IGMP) snooping. CGMP is available on Catalyst 2900 XL and 3500 XL switches. IGMP snooping is available on Catalyst 2950 and 3550 switches.
To enable and disable CGMP and perform related configuration tasks, choose Device > CGMP and use the CGMP window.
To enable and disable IGMP snooping and perform related configuration tasks, choose Device > IGMP Snooping and use the IGMP Snooping window.
"Configuring
IGMP Snooping and MVR," Catalyst 2950 Desktop Switch Software Configuration
Guide
"Configuring
the System," Catalyst 2900 XL and Catalyst 3500 XL Software Configuration
Guide