Quick Reference Guide

IGMP Snooping Commands | 275
igmp fast-leave
This command enables or disables IGMP Snooping fast-leave admin mode on a selected interface.
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.
Fast-leave admin mode should be enabled only on VLANs where only one host is connected to each
Layer 2 LAN port, to prevent 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
[no] igmp fast-leave
The no version of this command disables IGMP Snooping fast-leave admin mode on a
selected interface.
Default
disable
Mode
Interface Config; Interface Port Channel Config
Command
History
Related
Commands
igmp groupmembership-interval
This command sets the IGMP Group Membership Interval time o the selected interface or LAG (port
channel). The group membership interval time is the amount of time in seconds that a switch will wait
for a report from a particular group on a particular interface before deleting the interface from the entry.
Syntax
igmp groupmembership-interval 2-3600
The variable must be greater than the IGMPv3 maximum response time value. The range is 2 to 3600
seconds.
The no igmp groupmembership-interval command sets the IGMP v3 group membership
interval time on the interface to the default value.
Default
260 seconds
Mode
Interface Config; Interface Port Channel Config; Interface Range, which is indicated by the
(conf-if-range-interface)# prompt, such as (conf-if-range-vlan 10-20)#.
Version 2.5.1 Added to the new Interface Port Channel Config mode
Version 2.3
Revised from
set igmp fast-leave.
igmp enable (global) Enables IGMP Snooping on the system.
show igmpsnooping Displays IGMP Snooping status information.