488 IGMP Snooping Commands
Syntax
ip igmp snooping
vlan-id
no ip igmp snooping
Default Configuration
IGMP snooping is disabled on VLAN interfaces by default.
Command Mode
VLAN Configuration mode
User Guidelines
This command has no user guidelines.
Example
The following example enables IGMP snooping on VLAN 2.
console#vlan database
console(config-vlan)#ip igmp snooping 2
ip igmp snooping fast-leave
This command enables or disables IGMP Snooping fast-leave mode on a
selected VLAN. Enabling fast-leave allows the switch to immediately remove
the layer 2 LAN interface from its forwarding table entry upon receiving an
IGMP leave message for that multicast group without first sending out MAC-
based general queries to the interface. The no form of thi s command di sables
IGMP Snooping fast-leave mode on a VLAN.
You should enable fast-leave admin mode only on VLANs where only one host
is connected to each layer 2 LAN port. This setting prevents the inadvertent
dropping of the other hosts that were connected to the same layer 2 LAN port
but were still interested in receiving multicast traffic directed to that group.
Also, fast-leave processing is supported only with IGMP version 2 hosts.
Syntax
ip igmp snooping fast-leave
vlan-id
2CSPC4.XCT-SWUM2XX1.book Page 488 Monday, October 3, 2011 11:05 AM