Multicast Source Discovery Protocol (MSDP)Multicast source discovery protocol (MSDP) is supported on Dell Networking OS.Protocol OverviewMSDP is a Layer 3 protocol that connects IPv4 protocol-independent multicast-sparse mode (PIM-SM) domains. A domain in the contextof MSDP is a contiguous set of routers operating PIM within a common boundary defined by an exterior gateway protocol, such as bordergateway protocol (BGP).Each rendezvous point (RP) peers with every other RP via the transmission control protocol (TCP). Through this connection, peersadvertise the sources in their domain.1 When an RP in a PIM-SM domain receives a PIM register message from a source, it sends a source-active (SA) message to MSDPpeers, as shown in the following illustration.2 Each MSDP peer receives and forwards the message to its peers away from the originating RP.3 When an MSDP peer receives an SA message, it determines if there are any group members within the domain interested in any ofthe advertised sources. If there are, the receiving RP sends a join message to the originating RP, creating a shortest path tree (SPT)to the source.Figure 83. Multicast Source Discovery Protocol (MSDP)28534 Multicast Source Discovery Protocol (MSDP)
