Users Guide

Table Of Contents
Layer 2 Switching Commands 520
ip igmp snooping vlan immediate-leave
This command enables or disables IGMP Snooping immediate-leave mode
on a selected VLAN.
Syntax
ip igmp snooping vlan vlan-id immediate-leave
no ip igmp snooping vlan vlan-id immediate-leave
vlan id — A VLAN identifier (range 1-4093).
Default Configuration
IGMP snooping immediate-leave mode is disabled on VLANs by default.
Command Mode
Global Configuration mode
User Guidelines
Enabling immediate-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 this command disables IGMP
Snooping immediate-leave mode on a VLAN.
Enable immediate-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, immediate-leave processing is supported only with IGMP version
2 hosts.
Example
The following example enables IGMP snooping immediate-leave mode on
VLAN 2.
console(config)#ip igmp snooping vlan 2 immediate-leave