Disabling Multicast Flooding During A Tcn Event - Cisco ME 3400G-2CS - Ethernet Access Switch Software Configuration Manual

Configuring IGMP Snooping
Beginning in privileged EXEC mode, follow these steps to enable the switch sends the global leave
message whether or not it is the spanning-tree root:
Command
Step 1 configure terminal
Step 2
ip igmp snooping tcn query solicit
Step 3
end
Step 4
show ip igmp snooping
Step 5 copy running-config startup-config
To return to the default query solicitation, use the no ip igmp snooping tcn query solicit global
configuration command.

Disabling Multicast Flooding During a TCN Event

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 use the ip igmp
snooping tcn flood interface configuration command to control this behavior.
Beginning in privileged EXEC mode, follow these steps to disable multicast flooding on an interface:
Command
Step 1
configure terminal
Step 2 interface interface-id
Step 3 no shutdown
Step 4 no ip igmp snooping tcn flood
Step 5
exit
Step 6 show ip igmp snooping
Step 7 copy running-config startup-config
To re-enable multicast flooding on an interface, use the ip igmp snooping tcn flood interface
configuration command.
Cisco ME 3400 Ethernet Access Switch Software Configuration Guide
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Purpose
Enter global configuration mode.
Send an IGMP leave message (global leave) to speed the process of
recovering from the flood mode caused during a TCN event. By
default, query solicitation is disabled.
Return to privileged EXEC mode.
Verify the TCN settings.
(Optional) Save your entries in the configuration file.
Purpose
Enter global configuration mode.
Specify the interface to be configured, and enter interface
configuration mode.
Enable the port, if necessary. By default, user network interfaces
(UNIs) are disabled, and network node interfaces (NNIs) are enabled.
Disable the flooding of multicast traffic during a spanning-tree TCN
event.
By default, multicast flooding is enabled on an interface.
Return to privileged EXEC mode.
Verify the TCN settings.
(Optional) Save your entries in the configuration file.
Chapter 20 Configuring IGMP Snooping and MVR
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