Cisco ASA 5505 - Manual (Page 506)

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Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter 26 Configuring Multicast Routing
Configuration Example for Multicast Routing
Configuring a Multicast Boundary
Address scoping defines domain boundaries so that domains with RPs that have the same IP address do
not leak into each other. Scoping is performed on the subnet boundaries within large domains and on the
boundaries between the domain and the Internet.
You can set up an administratively scoped boundary on an interface for multicast group addresses by
entering the multicast boundary command. IANA has designated the multicast address range from
239.0.0.0 to 239.255.255.255 as the administratively scoped addresses. This range of addresses can be
reused in domains administered by different organizations. The addresses would be considered local, not
globally unique.
A standard ACL defines the range of affected addresses. When a boundary is set up, no multicast data
packets are allowed to flow across the boundary from either direction. The boundary allows the same
multicast group address to be reused in different administrative domains.
You can configure, examine, and filter Auto-RP discovery and announcement messages at the
administratively scoped boundary by entering the the filter-autorp keyword. Any Auto-RP group range
announcements from the Auto-RP packets that are denied by the boundary ACL are removed. An
Auto-RP group range announcement is permitted and passed by the boundary only if all addresses in the
Auto-RP group range are permitted by the boundary ACL. If any address is not permitted, the entire
group range is filtered and removed from the Auto-RP message before the Auto-RP message is
forwarded.
To configure a multicast boundary, enter the following command:
Configuration Example for Multicast Routing
The following example shows how to enable and configure multicast routing with various optional
processes:
Step 1 Enable multicast routing:
hostname(config)# multicast-routing
Step 2 Configure a static multicast route:
hostname(config)# mroute src_ip src_mask {input_if_name | rpf_neighbor} [distance]
hostname(config)# exit
Step 3 Configure the ASA to be a member of a multicast group:
hostname(config)# interface
hostname(config-if)# igmp join-group group-address
Command Purpose
multicast boundary acl [filter-autorp]
Example:
hostname(config-if)# multicast boundary
acl1 [filter-autorp]
Configures a multicast boundary.