Multicast - Using MSDP with Anycast RPs
In a Multicast environment where Anycast Rendezvous Points (RPs) are deployed, the Multicast Source Discovery Protocol (MSDP) plays an important role in synchronizing the multicast state information between multiple Anycast RPs.
Here’s how MSDP helps in this scenario:
- Multicast Source Discovery: MSDP allows the Anycast RPs to discover active multicast sources (sources sending multicast traffic) in other networks or regions. When an RP receives a multicast stream from a source, it generates a "Source-Active (SA) message," which includes information about the source and the multicast group.
- SA Message Propagation: The SA messages generated by one RP are shared with the other Anycast RPs using MSDP. This synchronization ensures that all Anycast RPs have knowledge of the active multicast sources, even if the source registered with only one of the RPs initially.
- Consistency Across RPs: By sharing SA messages, MSDP helps maintain consistency of multicast source information across all the Anycast RPs in the multicast domain. This allows any of the RPs to respond to Join messages from receivers, regardless of which RP the receivers are contacting. This way, the load is shared, and redundancy is maintained.
- Load Sharing and Redundancy: In an Anycast RP deployment, multiple RPs share the load of multicast traffic. MSDP ensures that if one RP learns about a multicast source, all the RPs are aware of it. This allows multiple RPs to serve as entry points for receivers joining a multicast group, providing load distribution and redundancy in case one RP fails.
MSDP facilitates the synchronization of multicast source information between Anycast RPs by exchanging SA messages, ensuring that all RPs in the multicast domain are aware of the active sources, which is critical for seamless and efficient multicast delivery.
Instead of using MSDP with Anycast PRs, you can also use Auto-RP or BSR.
Links
https://networklessons.com/multicast/multicast-anycast-rp-configuration-cisco-ios