46-44
Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter46 Configuring IP Multicast Routing
Configuring Optional Multicast Routing Features
Beginning in privileged EXEC mode, follow these steps to configure the switch itself to be a statically
connected member of a group (and enable fast switching). This procedure is optional.
To remove the switch as a member of the group, use the no ip igmp static-group group-address interface
configuration command.
Configuring Optional Multicast Routing Features
These sections describe how to configure optional multicast routing features:
Features for Layer 2 connectivity and MBONE multimedia conference session and set up:
Enabling CGMP Server Support, page46-44 (optional)
Configuring sdr Listener Support, page46-45 (optional)
Features that control bandwidth utilization:
Configuring an IP Multicast Boundary, page46-47 (optional)
Procedure for configuring a multicast within a VPN routing/forwarding (VRF) table:
Configuring Multicast VRFs, page38-80

Enabling CGMP Server Support

The switch serves as a CGMP server for devices that do not support IGMP snooping but have CGMP
client functionality. CGMP is a protocol used on Cisco routers and multilayer switches connected to
Layer 2 Catalyst switches to perform tasks similar to those performed by IGMP. CGMP is necessary
because the Layer 2 switch cannot distinguish between IP multicast data packets and IGMP report
messages, which are both at the MAC-level and are addressed to the same group address.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface interface-id Specify the interface to be configured, and enter interface configuration
mode.
Step3 ip igmp static-group group-address Configure the switch as a statically connected member of a group.
By default, this feature is disabled.
Step4 end Return to privileged EXEC mode.
Step5 show ip igmp interface [interface-id] Verify your entries.
Step6 copy running-config startup-config (Optional) Save your entries in the configuration file.