Cisco Catalyst 3550 Command Reference Manual page 143

Chapter 2 Cisco IOS Commands
Defaults
IGMP snooping is globally enabled on the switch.
IGMP snooping is enabled on VLAN interfaces.
IGMP immediate-leave processing is disabled.
The default learning method is pim-dvmrp—to snoop IGMP queries and PIM-DVMRP packets.
By default, there are no ports specified as members of a static multicast group.
By default, there are no multicast router ports.
Command Modes
Global configuration
Command History Release
12.1(4)EA1
Usage Guidelines When IGMP snooping is enabled globally, it is enabled in all the existing VLAN interfaces. When IGMP
snooping is disabled globally, it is disabled in all the existing VLAN interfaces.
The configuration is saved in nonvolatile RAM (NVRAM).
You should configure only the Immediate Leave feature when there is a maximum of one receiver on
every port in the VLAN. The configuration is saved in NVRAM.
The Immediate Leave feature is supported only with IGMP version 2 hosts.
The CGMP learn method is useful for cutting down on control traffic.
The configured learn method is saved in NVRAM.
The static keyword is used for configuring the IGMP member ports statically.
The static ports and groups are saved in NVRAM.
Examples
This example shows how to globally enable IGMP snooping:
Switch(config)# ip igmp snooping
This example shows how to globally disable IGMP snooping:
Switch(config)# no ip igmp snooping
This example shows how to enable IGMP snooping on VLAN 1:
Switch(config)# ip igmp snooping vlan 1
This example shows how to disable IGMP snooping on VLAN 1:
Switch(config)# no ip igmp snooping vlan 1
This example shows how to enable IGMP immediate-leave processing on VLAN 1:
Switch(config)# ip igmp snooping vlan 1 immediate-leave
This example shows how to disable IGMP immediate-leave processing on VLAN 1:
Switch(config)# no ip igmp snooping vlan 1 immediate-leave
78-11195-09
Modification
This command was first introduced.
Catalyst 3550 Multilayer Switch Command Reference
ip igmp snooping
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