Administrator Guide

Layer 2 Switching Commands 482
User Guidelines
This command has no user guidelines.
Example
The following example shows IGMP snooping mrouter information.
console#show ip igmp snooping mrouter
VLAN ID Port
------- -----------
10 Gi2/0/1
ip igmp snooping vlan immediate-leave
This command enables or disables IGMP Snooping immediate-leave mode
on a selected VLAN. 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.
You should 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.
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