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Catalyst 3560 Switch Software Configuration Guide
OL-8553-06
Chapter 23 Configuring IGMP Snooping and MVR
Displaying IGMP Snooping Information
This example shows how to set the IGMP snooping querier source address to 10.0.0.64:
Switch# configure terminal
Switch(config)# ip igmp snooping querier 10.0.0.64
Switch(config)# end
This example shows how to set the IGMP snooping querier maximum response time to 25 seconds:
Switch# configure terminal
Switch(config)# ip igmp snooping querier query-interval 25
Switch(config)# end
This example shows how to set the IGMP snooping querier timeout to 60 seconds:
Switch# configure terminal
Switch(config)# ip igmp snooping querier timeout expiry 60
Switch(config)# end
This example shows how to set the IGMP snooping querier feature to version 2:
Switch# configure terminal
Switch(config)# no ip igmp snooping querier version 2
Switch(config)# end

Disabling IGMP Report Suppression

Note IGMP report suppression is supported only when the multicast query has IGMPv1 and IGMPv2 reports.
This feature is not supported when the query includes IGMPv3 reports.
IGMP report suppression is enabled by default. When it is enabled, the switch forwards only one IGMP
report per multicast router query. When report suppression is disabled, all IGMP reports are forwarded
to the multicast routers.
Beginning in privileged EXEC mode, follow these steps to disable IGMP report suppression:
To re-enable IGMP report suppression, use the ip igmp snooping report-suppression global
configuration command.
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.
Command Purpose
Step 1 configure terminal Enter global configuration mode.
Step 2 no ip igmp snooping report-suppression Disable IGMP report suppression.
Step 3 end Return to privileged EXEC mode.
Step 4 show ip igmp snooping Verify that IGMP report suppression is disabled.
Step 5 copy running-config startup-config (Optional) Save your entries in the configuration file.