Setting The Maximum Number Of Igmp Groups; Configuring The Igmp Throttling Action - Cisco Catalyst 2950 Software Configuration Manual

Configuring IGMP Filtering and Throttling

Setting the Maximum Number of IGMP Groups

You can set the maximum number of IGMP groups that a Layer 2 interface can join by using the ip igmp
max-groups interface configuration command. Use the no form of this command to set the maximum
back to the default, which is no limit.
You can use this command on an logical EtherChannel interface but cannot use it on ports that belong
to an EtherChannel port group.
Beginning in privileged EXEC mode, follow these steps to set the maximum number of IGMP groups in
the forwarding table:
Command
Step 1
configure terminal
Step 2 interface interface-id
Step 3 ip igmp max-groups number
Step 4 end
Step 5 show running-configuration interface
interface-id
Step 6
copy running-config startup-config
To remove the maximum group limitation and return to the default of no maximum, use the no ip igmp
max-groups interface configuration command.
This example shows how to limit to 25 the number of IGMP groups that an interface can join.
Switch(config)# interface fastethernet0/2
Switch(config-if)# ip igmp max-groups 25
Switch(config-if)# end

Configuring the IGMP Throttling Action

After you set the maximum number of IGMP groups that a Layer 2 interface can join, you can configure
an interface to remove a randomly selected multicast entry in the forwarding table and to add the next
IGMP group to it by using the ip igmp max-groups action replace interface configuration command.
Use the no form of this command to return to the default, which is to drop the IGMP join report.
Follow these guidelines when configuring the IGMP throttling action:
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You can use this command on a logical EtherChannel interface but cannot use it on ports that belong
to an EtherChannel port group.
When the maximum group limitation is set to the default (no maximum), entering the ip igmp
max-groups action {deny | replace} command has no effect.
Purpose
Enter global configuration mode.
Enter interface configuration mode by entering the physical interface to
configure. The interface can be a Layer 2 port that does not belong to an
EtherChannel group or a EtherChannel interface.
Set the maximum number of IGMP groups that the interface can join.
The range is from 0 to 4294967294. The default is to have no maximum
set.
Return to privileged EXEC mode.
Verify the configuration.
(Optional) Save your entries in the configuration file.
Chapter 20 Configuring IGMP Snooping and MVR
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