Enabling Rgmp On Layer 3 Interfaces - Cisco 7604 Configuration Manual

Chapter 32 Configuring RGMP
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Enabling RGMP on Layer 3 Interfaces

To enable RGMP on a Layer 3 interface, perform this task:
Command
Step 1
Router(config)# interface {{vlan vlan_ID } |
1
{ type slot/port } | {port-channel number }}
Step 2
Router(config-if)# ip rgmp
Router(config-if)# no ip rgmp
Step 3
Router(config-if)# end
Step 4
Router# debug ip rgmp [ name_or_group_address ]
1. type = ethernet, fastethernet, gigabitethernet, tengigabitethernet, or ge-wan
This example shows how to configure RGMP on FastEthernet port 3/3:
Router# configure terminal
Enter configuration commands, one per line.
Router(config)# interface fastethernet 3/3
Router(config-if)# ip rgmp
Router(config-if)# end
Router#
For additional information (including configuration examples and troubleshooting information), see the
Tip
documents listed on this page:
http://www.cisco.com/en/US/products/hw/routers/ps368/tsd_products_support_series_home.html
OL-4266-08
CGMP is not supported in networks where RGMP is enabled on routers. You cannot enable both
RGMP and CGMP on a Layer 3 interface. If RGMP is enabled on a Layer 3 interface, CGMP is
silently disabled and vice versa.
The following properties of RGMP are the same as for IGMP snooping:
– RGMP constrains traffic based on the multicast group, not on the sender's IP address.
– If spanning tree topology changes occur in the network, the state is not flushed as it is with
Cisco Group Management Protocol (CGMP).
RGMP does not constrain traffic for multicast groups 224.0.0.x (x = 0...255), which allows use
–
of PIMv2 bootstrap router (BSR) in an RGMP-controlled network.
RGMP in Cisco network devices operates on MAC addresses, not on IP multicast addresses.
–
Because multiple IP multicast addresses can map to one MAC address (see RFC 1112), RGMP
cannot differentiate between the IP multicast groups that might map to a MAC address.
The capability of the Cisco 7600 series router to constrain traffic is limited by its
–
content-addressable memory (CAM) table capacity.
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
Enabling RGMP on Layer 3 Interfaces
Purpose
Selects an interface to configure.
Enables RGMP on the Layer 3 interface.
Disables RGMP on the Layer 3 interface.
Exits configuration mode.
(Optional) Monitors RGMP.
End with CNTL/Z.
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