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Catalyst 2950 Desktop Switch Software Configuration Guide
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Chapter 17 Configuring IGMP Snooping and M V R Configuring IGMP Snooping
This example shows how to statically configure a host on an interface and verify the configuration:
Switch# configure terminal
Switch(config)# ip igmp snooping vlan 1 static 0100.5e00.0203 interface gigabitethernet0/1
Switch(config)# end
Switch# show mac address-table multicast vlan 1
Vlan Mac Address Type Ports
---- ----------- ---- -----
1 0100.5e00.0203 USER Gi0/1

Enabling IGMP Immediate-Leave Processing

When you ena ble IGMP Immediat e-Leave processing, the switc h immedia tely removes a port when it
detects an IGMP version 2 leav e message on that port. You should use the Immediate-Leave feature only
when the r e is a si ng le re ce iver pre sen t on every por t in th e V LAN .
Immediate Leave is supported with only IGMP version 2 hosts.
Beginning i n privileged EX EC mode , follow th ese s teps t o ena ble IG MP Im media te-L eave processi ng :
To disable IGMP Immediate-Leave on a VLAN, use the no ip igmp snooping vlan vlan-id
immediate-leave global configur ation c om mand.
This example shows how to enable IG MP immed iate-leave processing on V LAN 130 a nd 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

Disabling IP Multicast-Source-Only Learning

The IP multicast-source-only learning method is enabled by default. The switch learns the IP multicast
group fr om the IP m ulticast data stre am and only f orwards traffic to the m ulticast router ports.
Command Purpose
Step 1 configure terminal Enter globa l configurati on 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 (Optiona l) Save your entries in the co nfigurati on file.