Cisco CATALYST 2960 Command Reference Guide

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Catalyst 2960 Switch Command Reference
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Chapter 2 Catalyst 2960 Switch Cisco IOS Commands
ip igmp snooping tcn flood
ip igmp snooping tcn flood
Use the ip igmp snooping tcn flood interface configuration command 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 gigabitethernet0/2
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(25)FX 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 2960 Specifications

General

Manageable	Yes
Stacking	No
Model	Catalyst 2960 Series Switches
Power over Ethernet (PoE)	Available on some models (IEEE 802.3af)
VLANs	255 active VLANs
Features	QoS
Operating Temperature	32 to 113°F (0 to 45°C)
Relative Humidity	10% to 85% non-condensing
Power Consumption	Varies by model (30W to 400W)