Cisco ASA Series Cli Configuration Manual page 718

Customizing Multicast Routing
IGMP uses group addresses (Class D IP address) as group identifiers. Host group address can be in the
range of 224.0.0.0 to 239.255.255.255. The address 224.0.0.0 is never assigned to any group. The
address 224.0.0.1 is assigned to all systems on a subnet. The address 224.0.0.2 is assigned to all routers
on a subnet.
When you enable multicast routing on the ASA, IGMP Version 2 is automatically enabled on all
interfaces.
Note
Only the no igmp command appears in the interface configuration when you use the show run
command. If the multicast-routing command appears in the device configuration, then IGMP is
automatically enabled on all interfaces.
This section describes how to configure optional IGMP setting on a per-interface basis and includes the
following topics:
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Disabling IGMP on an Interface
You can disable IGMP on specific interfaces. This information is useful if you know that there are no
multicast hosts on a specific interface and you want to prevent the ASA from sending host query
messages on that interface.
To disable IGMP on an interface, enter the following command:
Command
no igmp
Example:
hostname(config-if)# no igmp
Note
Only the no igmp command appears in the interface configuration.
Cisco ASA Series CLI Configuration Guide
1-6
Disabling IGMP on an Interface, page 1-6
Configuring IGMP Group Membership, page 1-7
Configuring a Statically Joined IGMP Group, page 1-7
Controlling Access to Multicast Groups, page 1-8
Limiting the Number of IGMP States on an Interface, page 1-8
Modifying the Query Messages to Multicast Groups, page 1-8
Changing the IGMP Version, page 1-9
Purpose
Disables IGMP on an interface.
To reenable IGMP on an interface, use the igmp command.
Chapter 1 Configuring Multicast Routing