Displaying Igmp Snooping Information - Cisco 4500M Software Manual

Chapter 18 Configuring IGMP Snooping and Filtering
This example shows how to modify the switch to stop flooding multicast traffic after four queries:
Switch(config)# ip igmp snooping tcn flood query count 4
Switch(config)# end
Switch#
When a spanning tree root switch receives a topology change in an IGMP snooping-enabled VLAN, the
switch issues a query solicitation that causes an IOS router to send out one or more general queries. The
new command ip igmp snooping tcn query solicit causes the switch to send the query solicitation
whenever it notices a topology change, even if that switch is not the spanning tree root.
This command operates at the global configuration level.
By default, query solicitation is disabled unless the switch is the spanning tree root. The default keyword
restores the default behavior.
To direct a switch to send a query solicitation, perform this task:
Command
Step 1
Switch(config)#
ip igmp snooping tcn query solicit
Step 2
Switch(config)# end
This example shows how to configure the switch to send a query solicitation upon detecting a TCN:
Switch(config)# ip igmp snooping tcn query solicit
Switch(config)# end
Switch#

Displaying IGMP Snooping Information

The following sections show how to display IGMP snooping information:
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OL-6696-01
Displaying Querier Information, page 18-12
Displaying IGMP Host Membership Information, page 18-12
Displaying Group Information, page 18-13
Displaying Multicast Router Interfaces, page 18-14
Displaying MAC Address Multicast Entries, page 18-15
Displaying IGMP Snooping Information on a VLAN Interface, page 18-15
Displaying IGMP Snooping Information
Purpose
Configures the switch to send a query solicitation when
a TCN is detected.
To stop the switch from sending a query solicitation (if
it's not a spanning tree root switch), enter this command:
no ip igmp snooping tcn query solicit
Exits configuration mode.
Software Configuration Guide—Release 12.2(25)EW
18-11