Cisco ASA 5505 - Manual (Page 497)

26-5
Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter 26 Configuring Multicast Routing
Customizing Multicast Routing
Configuring IGMP Features
IP hosts use the Internet Group Management Protocol (IGMP) to report their group memberships to
directly connected multicast routers.
IGMP is used to dynamically register individual hosts in a multicast group on a particular LAN. Hosts
identify group memberships by sending IGMP messages to their local multicast router. Under IGMP,
routers listen to IGMP messages and periodically send out queries to discover which groups are active
or inactive on a particular subnet.
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:
• Disabling IGMP on an Interface, page 26-6
• Configuring IGMP Group Membership, page 26-6
• Configuring a Statically Joined IGMP Group, page 26-6
• Controlling Access to Multicast Groups, page 26-7
• Limiting the Number of IGMP States on an Interface, page 26-7
• Modifying the Query Messages to Multicast Groups, page 26-8
• Changing the IGMP Version, page 26-9
Command Purpose
mroute src_ip src_mask {input_if_name |
rpf_neighbor} [distance]
Example:
hostname(config)# mroute src_ip src_mask
{input_if_name | rpf_neighbor} [distance]
Configures a static multicast route.
mroute src_ip src_mask input_if_name
[dense output_if_name] [distance]
Example:
hostname(config)# mroute src_ip src_mask
input_if_name [dense output_if_name]
[distance]
Configures a static multicast route for a stub area.
The dense output_if_name keyword and argument pair is only supported
for stub multicast routing.