Cisco 3845 - Security Bundle Router

18-9
Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 18 Configuring IGMP Snooping
Configuring IGMP Snooping
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
Follow 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.
Beginning in privileged EXEC mode, follow these steps to enable the IGMP configurable-leave timer:
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.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
ip igmp snooping
last-member-query-interval time
Configure the IGMP leave timer globally. The range is 100 to
32768 milliseconds. The default is 1000 seconds.
Step 3
ip igmp snooping vlan vlan-id
last-member-query-interval time
(Optional) Configure the IGMP leave time on the VLAN interface. The
range is 100 to 32768 milliseconds.
Note Configuring the leave time on a VLAN overrides the globally
configured timer.
Step 4
end Return to privileged EXEC mode.
Step 5
show ip igmp snooping (Optional) Display the configured IGMP leave time.
Step 6
copy running-config startup-config (Optional) Save your entries in the configuration file.