Cisco IOS Cookbook, 2nd Edition

Using MSDP to Discover External Sources

Problem

You want to use MSDP to discover information about multicast sources in other Autonomous Systems.

Solution

The typical way to configure Multicast Source Discovery Protocol (MSDP) involves first selecting one of your MBGP routers as the RP for your internal network. Then you set up an MSDP peer relationship with the RP in another Autonomous System, which is usually an MBGP peer router in the next domain. The following configuration includes commands required to configure the router as an RP for the internal network using BSR, as discussed in Recipe 23.2, although you could just as easily use Auto-RP. It also includes configuration to prevent local multicast traffic from leaking into the neighboring network, as discussed in Recipes 23.14 and 23.15. And it includes MBGP configuration as in Recipe 23.16:

Router-ASBR1#configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
Router-ASBR1(config)#ip multicast-routing
Router-ASBR1(config)#interface Loopback0
Router-ASBR1(config-if)#ip address 192.168.12.1 255.255.255.255
Router-ASBR1(config-if)# ip pim sparse-mode
Router-ASBR1(config-if)#interface FastEthernet0/0
Router-ASBR1(config-if)#ip address 192.168.1.1 255.255.255.0
Router-ASBR1(config-if)#ip pim sparse-mode
Router-ASBR1(config-if)#exit
Router-ASBR1(config)#interface Serial1/0
Router-ASBR1(config-if)#ip address 192.168.2.5 255.255.255.252
Router-ASBR1(config-if)#ip multicast boundary 15
Router-ASBR1(config-if)#