11-9
Catalyst 3550 Multilayer Switch Software Configuration Guide
78-11194-03
Chapter 11 Configuring IGMP Snooping and MVR
Displaying IGMP Snooping Information
Enabling IGMP Immediate-Leave Processing
When you enable IGMP Immediate-Leave processing, the switch immediately removes a port when it
detects an IGMP version 2 leave message on that port. You should use the Immediate-Leave feature only
when there is a single receiver present on every port in the VLAN.
Immediate Leave is supported with only IGMP version 2 hosts.
Beginning in privileged EXEC mode, follow these steps to enable IGMP Immediate-Leave processing:
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 processing on VLAN 130 and verify the
configuration:
Switch# configure terminal
Switch(config)# ip igmp snooping vlan 130 immediate-leave
Switch(config)# end
Switch# show ip igmp snooping vlan 130
vlan 130
----------
IGMP snooping is globally enabled
IGMP snooping is enabled on this Vlan
IGMP snooping immediate-leave is enabled on this Vlan
IGMP snooping mrouter learn mode is pim-dvmrp on this Vlan
IGMP snooping is running in IGMP_ONLY mode on this Vlan
Displaying IGMP Snooping Information
You can display IGMP snooping information for dynamically learned and statically configured router
ports and VLAN interfaces. You can also display MAC address multicast entries for a VLAN configured
for IGMP snooping.
To display IGMP snooping information, use one or more of the privileged EXEC commands in
Table 11-4
.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode
Step 2
ip igmp snooping vlan vlan-id
immediate-leave
Enable IGMP Immediate-Leave processing 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.
Step 5
copy running-config startup-config
(Optional) Save your entries in the configuration file.