Cisco ME 3600X, Command Reference Manual

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Cisco ME 3800X and ME 3600X Switch Command Reference
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Chapter 2 Cisco ME 3800X and ME 3600X Switch Cisco IOS Commands
ip igmp snooping tcn
ip igmp snooping tcn
To configure the Internet Group Management Protocol (IGMP) Topology Change Notification (TCN)
behavior, use the
ip igmp snooping tcn command in global configuration mode. To return to the default
settings, use the no form of this command.
ip igmp snooping tcn { flood query count count | query solicit }
no ip igmp snooping tcn { flood query count | query solicit }
Syntax Description
Defaults The TCN flood query count is 2.
The TCN query solicitation is disabled.
Command Modes Global configuration
Command History
Usage Guidelines
You can prevent the loss of the multicast traffic that might occur because of a topology change by using
this command. 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 one general query. If you set the count to 7, the
flooding of multicast traffic due to the TCN event lasts until seven general queries are received. Groups
are relearned based on the general queries received during the TCN event.
You can verify your settings by entering the show ip igmp snooping privileged EXEC command.
Examples This example shows how to specify 7 as the number of IGMP general queries for which the multicast
traffic is flooded:
Switch(config)# no ip igmp snooping tcn flood query count 7
Related Commands
flood query count count Specifies the number of IGMP general queries for which the multicast
traffic is flooded. The range is 1 to 10.
query solicit Sends an IGMP leave message (global leave) to speed the process of
recovering from the flood mode caused during a TCN event.
Release Modification
12.2(52)EY This command was introduced.
Command Description
ip igmp snooping Enables IGMP snooping on the switch or on a VLAN.
ip igmp snooping tcn flood Specifies flooding on an interface as the IGMP snooping spanning-tree
TCN behavior.
show ip igmp snooping Displays the IGMP snooping configuration of the switch or the VLAN.