Configuring the RP Mapping Agent

Configuring the RP Mapping Agent
This router is in charge of learning all the rendezvous point routers in the network, along with
the multicast group assignments that each RP advertises. The Mapping Agent then tells all the
routers within the multicast network which RP should be used for their source.
628 Chapter 19  Understanding and Configuring Multicast Operation
This is done with the ip pim send-rp-discovery scope ttl command. As you can see, this
command is similar to the command in the preceding section. The scope defines the TTL value for
the discovery. After the TTL is reached, the discovery packets are dropped. Here is an example:
Terry_3640#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Terry_3640(config)#ip pim send-rp-discovery scope 23
Terry_3640(config)#^Z
Terry_3640
In this example, you can see that the TTL value was set to 23. This means that after 23 hops, the
discovery has expired. This command actually assigns to the router the role of RP Mapping Agent.
This concludes the tasks for configuring a rendezvous point in a multicast network. Keep in mind
that the RP Mapping Agent can be an RP, although it doesn’t have to be. The Mapping Agent’s role
is to learn of all the deployed rendezvous points throughout the network and then advertise which
groups are available via the closest RP for all multicast-enabled routers in the network.