21-19
Catalyst 2928 Switch Software Configuration Guide
OL-23389-01
Chapter 21 Configuring IGMP Snooping
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 a 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:
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 a port can join.
Switch(config)#
interface gigabitethernet0/2
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 replace the existing group with the new group for which the IGMP report was received
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:
•
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.
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
interface
interface-id
Specify the interface to be configured, and enter interface configuration
mode. The interface can be a Layer 2 port that does not belong to an
EtherChannel group or a EtherChannel interface.
Step 3
ip igmp max-groups
number
Set the maximum number of IGMP groups that the interface can join.
The range is 0 to 4294967294. The default is to have no maximum set.
Step 4
end
Return to privileged EXEC mode.
Step 5
show running-config interface
interface-id
Verify the configuration.
Step 6
copy running-config startup-config
(Optional) Save your entries in the configuration file.
