Cisco Catalyst 3750-X Command Reference

2-296
Catalyst 3750-X and 3560-X Switch Command Reference
OL-29704-01
Chapter 2 Catalyst 3750-X and 3560-X Switch Cisco IOS Commands
ip igmp snooping tcn flood
ip igmp snooping tcn flood
Use the ip igmp snooping tcn flood interface configuration command on the switch stack or on a
standalone switch to specify multicast flooding as the Internet Group Management Protocol (IGMP)
snooping spanning-tree Topology Change Notification (TCN) behavior. Use the no form of this
command to disable the multicast flooding.
ip igmp snooping tcn flood
no ip igmp snooping tcn flood
Syntax Description This command has no arguments or keywords.
Defaults Multicast flooding is enabled on an interface during a spanning-tree TCN event.
Command Modes Interface configuration
Command History
Usage Guidelines When the switch receives a TCN, multicast traffic is flooded to all the ports until two general queries are
received. If the switch has many ports with attached hosts that are subscribed to different multicast
groups, the flooding might exceed the capacity of the link and cause packet loss.
You can change the flooding query count by using the ip igmp snooping tcn flood query count count
global configuration command.
Examples This example shows how to disable the multicast flooding on an interface:
Switch(config)# interface gigabitethernet1/0/2
Switch(config-if)# no ip igmp snooping tcn flood
You can verify your settings by entering the show ip igmp snooping privileged EXEC command.
Related Commands
Release Modification
12.2(53)SE2 This command was introduced.
Command Description
ip igmp snooping Enables IGMP snooping on the switch or on a VLAN.
ip igmp snooping tcn Configures the IGMP TCN behavior on the switch.
show ip igmp snooping Displays the IGMP snooping configuration of the switch or the VLAN.

Cisco Catalyst 3750-X Specifications

General

Brand	Cisco
Model	Catalyst 3750-X
Category	Switch
Language	English