Configuring Rgmp; Understanding How Rgmp Works - Cisco WS-SUP32-GE-3B - Supervisor Engine 32 Software Configuration Manual

Configuring RGMP

This chapter supplements the information and procedures about Router-Port Group Management
Protocol (RGMP) in the Release 12.2 publication at this URL:
http://www.cisco.com/en/US/docs/ios/12_2/ip/configuration/guide/1cfrgmp.html
This chapter consists of these sections:
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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.
Note To use RGMP, you must enable IGMP snooping on the Catalyst 6500 series switch. IGMP snooping
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.
You must enable Protocol Independent Multicast (PIM) on all routers and switches for RGMP to work.
Note
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.
Table 29-1
OL-11439-03
Understanding How RGMP Works, page 29-1
Default RGMP Configuration, page 29-2
RGMP Configuration Guidelines and Restrictions, page 29-2
Enabling RGMP on Layer 3 Interfaces, page 29-3
provides a summary of the RGMP packet types.
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