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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 u
se 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 the
se 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.
