5-15 MSDP ConfigurationWhen configuring MSDP, go to these sections for information you are interested in:z MSDP Overviewz Configuring MSDP Basic Functionsz Configuring Connection Between MSDP Peersz Configuring SA Message Transmissionz Displaying and Maintaining MSDPz MSDP Configuration Examplez Troubleshooting MSDP Configurationz In this manual, the term “router” refers to a router in the generic sense or a Layer 3 Ethernet switchrunning an IP multicast protocol.z Because Multicast Source Discovery Protocol (MSDP) does not work with IRF Fabric feature,MSDP cannot be configured in IRF Fabric.MSDP OverviewIntroduction to MSDPMulticast Source Discovery Protocol (MSDP) is an inter-domain multicast solution developed toaddress the interconnection of Protocol Independent Multicast sparse mode (PIM-SM) domains. It isused to discover multicast source information in other PIM-SM domains.In the basic PIM-SM mode, a multicast source registers only with the RP in the local PIM-SM domain,and the multicast source information of a domain is isolated from that of another domain. As a result, theRP is aware of the source information only within the local domain and a multicast distribution tree isbuilt only within the local domain to deliver multicast data from a local multicast source to local receivers.If there is a mechanism that allows RPs of different PIM-SM domains to share their multicast sourceinformation, the local RP will be able to join multicast sources in other domains and multicast data canbe transmitted among different domains.MSDP achieves this objective. By establishing MSDP peer relationships among RPs of differentPIM-SM domains, source active (SA) messages can be forwarded among domains and the multicastsource information can be shared.
