Multicast Source Discovery Protocol (MSDP) Feature Overview and Configuration Guide
MSDP provides a mechanism to connect multiple PIM Sparse-Mode (PIM-SM) domains together. Each PIM-SM domain uses its own independent Rendezvous Point(s) (RPs), and does not have to depend on RPs in other domains.
MSDP can be used in three scenarios:
- Inter-domain: An MSDP-speaking router in a PIM-SM domain has an MSDP peering relationship with one or more MSDP-speaking router(s) in another domain(s). One MSDP-speaking router shares information on sources originating in its domain by sending SA (Source-Active) messages to its peer(s).
- Inter-domain Mesh Group: MSDP-speaking routers are configured as an MSDP Mesh.
- Intra-domain Mesh Group: MSDP is used between Anycast-RPs [RFC3446] within a single PIM-SM domain to synchronize information about the active sources being served by each Anycast-RP peer (by virtue of IGP reachability). MSDP peering used in this scenario is based on MSDP mesh groups, where typically two to tens of peers can comprise a given mesh group.
