Cisco® Field Manual: Catalyst® Switch Configuration

9-4. RGMP

• RGMP is a dynamic protocol that controls multicast traffic to multicast routers.

• With RGMP, a switch must still use IGMP snooping to constrain multicast traffic to interested hosts.

• RGMP can communicate only with routers that also run RGMP. Routers periodically send RGMP hello messages to switches.

• Routers that are interested in receiving traffic for a multicast group send an RGMP join request to the switch. Otherwise, the switch will not forward multicast traffic to the router.

• RGMP supports the use of PIM sparse mode only on multicast routers.

Configuration

1.	Enable IGMP snooping on the switch. See section “9-1: IGMP Snooping” for the necessary switch configuration steps.
2.	Enable PIM sparse mode multicast routing on a router. Refer ...