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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 26 Configuring IGMP Snooping and MVR
Configuring IGMP Snooping
This example shows how to statically configure a host on a port:
Switch# configure terminal
Switch(config)# ip igmp snooping vlan 105 static 224.2.4.12 interface gigabitethernet1/0/1
Switch(config)# end
Enabling IGMP Immediate Leave
When you enable IGMP Immediate Leave, the switch immediately removes a port when it detects an
IGMP Version 2 leave message on that port. You should only use the Immediate-Leave feature when
there is a single receiver present on every port in the VLAN.
Note Immediate Leave is supported only on IGMP Version 2 hosts.
Beginning in privileged EXEC mode, follow these steps to enable IGMP Immediate Leave:
To disable IGMP Immediate Leave on a VLAN, use the no ip igmp snooping vlan vlan-id
immediate-leave global configuration command.
This example shows how to enable IGMP Immediate Leave on VLAN 130:
Switch# configure terminal
Switch(config)# ip igmp snooping vlan 130 immediate-leave
Switch(config)# end
Configuring the IGMP Leave Timer
Follows these guidelines when configuring the IGMP leave timer:
You can configure the leave time globally or on a per-VLAN basis.
Configuring the leave time on a VLAN overrides the global setting.
The default leave time is 1000 milliseconds.
The IGMP configurable leave time is only supported on hosts running IGMP Version 2.
The actual leave latency in the network is usually the configured leave time. However, the leave time
might vary around the configured time, depending on real-time CPU load conditions, network delays
and the amount of traffic sent through the interface.
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 ip igmp snooping vlan vlan-id
immediate-leave Enable IGMP Immediate Leave on the VLAN interface.
Step 3 end Return to privileged EXEC mode.
Step 4 show ip igmp snooping vlan vlan-id Verify that Immediate Leave is enabled on the VLAN interface.
Step 5 copy running-config startup-config (Optional) Save your entries in the configuration file.