Chapter 22 Configuring Rgmp; Understanding How Rgmp Works - Cisco 6500 Series Software Configuration Manual

Configuring RGMP
This chapter describes how to configure Router-Port Group Management Protocol (RGMP). Release
12.1(3a)E3 and later releases support RGMP. This chapter consists of these sections:
•
•
•
•
For complete syntax and usage information for the commands used in this chapter, refer to the
Note
Catalyst 6500 Series Switch Cisco IOS Command Reference publication.

Understanding How RGMP Works

RGMP constrains multicast traffic that exits the Catalyst 6500 series switch through ports to which only
disinterested multicast routers are connected. RGMP reduces network congestion by forwarding
multicast traffic to only those routers that are configured to receive it.
To use RGMP, you must enable IGMP snooping on the Catalyst 6500 series switch. IGMP snooping
Note
constrains multicast traffic that exits through LAN ports to which hosts are connected. IGMP snooping
does not constrain traffic that exits through LAN ports to which one or more multicast routers are
connected.
Note You must enable Protocol Independent Multicast (PIM) on all routers and switches for RGMP to work.
Only PIM sparse mode is currently supported.
All routers on the network must be RGMP-capable. RGMP-capable routers send RGMP hello messages
periodically. The RGMP hello message tells the Catalyst 6500 series switch not to send multicast data
to the router unless an RGMP join message has also been sent to the Catalyst 6500 series switch from
that router. When an RGMP join message is sent, the router is able to receive multicast data.
To stop receiving multicast data, a router must send an RGMP leave message to the Catalyst 6500 series
switch. To disable RGMP on a router, the router must send an RGMP bye message to the Catalyst 6500
series switch.
78-14099-04
Understanding How RGMP Works, page 22-1
Default RGMP Configuration, page 22-2
RGMP Configuration Guidelines and Restrictions, page 22-2
Enabling RGMP on Layer 3 Interfaces, page 22-3
Catalyst 6500 Series Switch Cisco IOS Software Configuration Guide—Release 12.1 E
C H A P T E R
22
22-1