Cisco Catalyst 2960 Series, Configuration Manual

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DETAILED STEPS
Purpose Command or Action
Enables privileged EXEC mode. Enter your password if
prompted. enable
Example:
Switch> enable
Step 1
Enters the global configuration mode. configure terminal
Example:
Switch# configure terminal
Step 2
Specifies the number of IGMP general queries for which the
multicast traffic is flooded. ip igmp snooping tcn flood query count count
Example:
Switch(config)# ip igmp snooping tcn flood
Step 3
The range is 1 to 10. The default, the flooding query count is
2.
query count 3
To return to the default flooding query count, use the
no ip igmp snooping tcn flood query count global
configuration command.
Note
Returns to privileged EXEC mode.
end
Example:
Switch(config)#
end
Step 4
Verifies the TCN settings. show ip igmp snooping
Example:
Switch# show ip igmp snooping
Step 5
(Optional) Saves your entries in the configuration file.
copy running-config startup-config
Example:
Switch#
copy running-config startup-config
Step 6
Recovering from Flood Mode
When a topology change occurs, the spanning-tree root sends a special IGMP leave message (also known as
global leave) with the group multicast address 0.0.0.0. However, you can enable the switch to send the global
leave message whether it is the spanning-tree root or not. When the router receives this special leave, it
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
139
How to Configure IGMP Snooping and MVR