Cisco Systems 3560 Manual De Usuario

To globally reset the IGMP leave timer to the default setting, use the no ip igmp snooping 
last-member-query-interval global configuration command.

To remove the configured IGMP leave-time setting from the specified VLAN, use the no ip igmp 
snooping vlan vlan-id last-member-query-interval global configuration command.

These sections describe how to control flooded multicast traffic during a TCN event:

You can control the time that multicast traffic is flooded after a TCN event by using the ip igmp 
snooping tcn flood query count global configuration command. This command configures the number 
of general queries for which multicast data traffic is flooded after a TCN event. Some examples of TCN 
events are when the client changed its location and the receiver is on same port that was blocked but is 
now forwarding, and when a port went down without sending a leave message. 

If you set the TCN flood query count to 1 by using the ip igmp snooping tcn flood query count 
command, the flooding stops after receiving 1 general query. If you set the count to 7, the flooding until 
7 general queries are received. Groups are relearned based on the general queries received during the 
TCN event.

Beginning in privileged EXEC mode, follow these steps to configure the TCN flood query count:

To return to the default flooding query count, use the no ip igmp snooping tcn flood query count global 
configuration command. 

(Optional) Display the configured IGMP leave time.

(Optional) Save your entries in the configuration file.

Enter global configuration mode.

ip igmp snooping tcn flood query count 
count

Specify the number of IGMP general queries for which the multicast 
traffic is flooded. The range is 1 to 10. By default, the flooding query 
count is 2.

Return to privileged EXEC mode.

Verify the TCN settings. 

(Optional) Save your entries in the configuration file.