Cisco Catalyst 3750-X User Manual

26-8
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 26 Configuring IGMP Snooping and MVR
Configuring IGMP Snooping
You can configure the switch either to snoop on IGMP queries and PIM/DVMRP packets or to listen to
CGMP self-join or proxy-join packets. By default, the switch snoops on PIM/DVMRP packets on all
VLANs. To learn of multicast router ports through only CGMP packets, use the ip igmp snooping vlan
vlan-id mrouter learn cgmp global configuration command. When this command is entered, the router
listens to only CGMP self-join and CGMP proxy-join packets and to no other CGMP packets. To learn
of multicast router ports through only PIM-DVMRP packets, use the ip igmp snooping vlan vlan-id
mrouter learn pim-dvmrp global configuration command.
Note If you want to use CGMP as the learning method and no multicast routers in the VLAN are CGMP
proxy-enabled, you must enter the ip cgmp router-only command to dynamically access the router. For
more information, see Chapter 48, “Configuring IP Multicast Routing.”
Beginning in privileged EXEC mode, follow these steps to alter the method in which a VLAN interface
dynamically ac
cesses a multicast router:
To return to the default learning method, use the no ip i
gmp snooping vlan vlan-id mrouter learn cgmp
global configuration command.
This example shows how to configure IGMP snooping to use CGMP packets as the learning method:
Switch# configure terminal
Switch(config)# ip igmp snooping
vlan 1 mrouter learn cgmp
Switch(config)# end
Configuring a Multicast Router Port
To add a multicast router port (add a static connection to a multicast router), use the ip igmp snooping
vlan mrouter global configuration command on the switch.
Note Static connections to multicast routers are supported only on switch ports.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
ip igmp snooping vlan vlan-id mrouter
learn {cgmp | pim-dvmrp}
Enable IGMP snooping on a VLAN. The VLAN ID range is 1 to 1001
and 1006 to 4094.
Specify the multicast router le
arning method:
• cgmp—Listen for CGMP packets. This method is useful for
reducing control traffic.
• pim-dvmrp—Snoop on IGMP queries and PIM-DVMRP packets.
This is the default.
Step 3
end Return to privileged EXEC mode.
Step 4
show ip igmp snooping Verify the configuration.
Step 5
copy running-config startup-config (Optional) Save your entries in the configuration file.

Cisco Catalyst 3750-X Specifications

General

Switching Capacity	160 Gbps
Stacking Bandwidth	64 Gbps
Max Stacking Units	9
Layer Support	Layer 2 and Layer 3
Form Factor	Rack-mountable
DRAM	256 MB
Flash Memory	64 MB
Model	Cisco Catalyst 3750-X Series
Ports	24 or 48 10/100/1000 Ethernet ports
Uplink Interfaces	4 SFP or 2 SFP+
Features	StackWise Plus, EnergyWise
Image	IP Base or IP Services
Operating Temperature	0 to 40°C
Operating Humidity	10 to 85% noncondensing