Chapter 21
Configuring IGMP Snooping and MVR
If you want to use CGMP as the learning method and no multicast routers in the VLAN are CGMP
Note
proxy-enabled, you must enter the ip cgmp router-only command to dynamically access the router.
Beginning in privileged EXEC mode, follow these steps to alter the method in which a VLAN interface
dynamically accesses a multicast router:
Command
Step 1
configure terminal
Step 2
ip igmp snooping vlan vlan-id mrouter
learn {cgmp | pim-dvmrp}
Step 3
end
Step 4
show ip igmp snooping
Step 5
copy running-config startup-config
To return to the default learning method, use the no ip igmp 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.
Beginning in privileged EXEC mode, follow these steps to enable a static connection to a multicast
router:
Command
Step 1
configure terminal
Step 2
ip igmp snooping vlan vlan-id mrouter
interface interface-id
Step 3
end
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Purpose
Enter global configuration mode.
Enable IGMP snooping on a VLAN. The VLAN ID range is 1 to 1001
and 1006 to 4094.
Specify the multicast router learning 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.
Return to privileged EXEC mode.
Verify the configuration.
(Optional) Save your entries in the configuration file.
Purpose
Enter global configuration mode.
Specify the multicast router VLAN ID and the interface to the
multicast router.
The VLAN ID range is 1 to 1001 and 1006 to 4094.
•
The interface can be a physical interface or a port channel.
•
The port-channel range is 1 to 6.
Return to privileged EXEC mode.
Catalyst 2960 and 2960-S Switches Software Configuration Guide, Release 15.0(1)SE
Configuring IGMP Snooping
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