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Catalyst 3560 Switch Software Configuration Guide
OL-8553-06
Chapter 23 Configuring IGMP Snooping and MVR
Configuring IGMP Filtering and Throttling
IGMP filtering is applicable only to the dynamic learning of IP multicast group addresses, not static
configuration.
With the IGMP throttling feature, you can set the maximum number of IGMP groups that a Layer 2
interface can join. If the maximum number of IGMP groups is set, the IGMP snooping forwarding table
contains the maximum number of entries, and the interface receives an IGMP join report, you can
configure an interface to drop the IGMP report or to replace the randomly selected multicast entry with
the received IGMP report.
Note IGMPv3 join and leave messages are not supported on switches running IGMP filtering.
These sections contain this configuration information:
Default IGMP Filtering and Throttling Configuration, page 23-24
Configuring IGMP Profiles, page 23-24 (optional)
Applying IGMP Profiles, page 23-26 (optional)
Setting the Maximum Number of IGMP Groups, page 23-26 (optional)
Configuring the IGMP Throttling Action, page 23-27 (optional)
Default IGMP Filtering and Throttling Configuration
Tabl e 23-7 shows the default IGMP filtering configuration.
When the maximum number of groups is in forwarding table, the default IGMP throttling action is to
deny the IGMP report. For configuration guidelines, see the “Configuring the IGMP Throttling Action”
section on page 23-27.
Configuring IGMP Profiles
To configure an IGMP profile, use the ip igmp profile global configuration command with a profile
number to create an IGMP profile and to enter IGMP profile configuration mode. From this mode, you
can specify the parameters of the IGMP profile to be used for filtering IGMP join requests from a port.
When you are in IGMP profile configuration mode, you can create the profile by using these commands:
deny: Specifies that matching addresses are denied; this is the default.
exit: Exits from igmp-profile configuration mode.
no: Negates a command or returns to its defaults.
Tab l e 23-7 Default IGMP Filtering Configuration
Feature Default Setting
IGMP filters None applied
IGMP maximum number of IGMP groups No maximum set
IGMP profiles None defined
IGMP profile action Deny the range addresses