Multicast - AutoRP

Multicast PIM Auto RP is a protocol that is used to automatically find the Rendezvous Point (RP) in a multicast PIM sparse mode network. It is similar to the open PIM Bootstrap (BSR), but is a Cisco proprietary protocol.

AutoRP is specifically designed to simplify the management of RP information in multicast networks. AutoRP automates the distribution of RP information reducing the need for manual RP configuration on each router.

Key components of AutoRP include:

• Mapping Agents: These routers receive RP announcements from potential RPs and create a mapping of multicast group addresses to RPs. They then distribute this mapping to all other routers in the network. Some design considerations include:
  • Multicast Mapping Agent and RP placement
  • Multicast mapping agent IGMP membership report
  • Multicast PIM Auto RP and Mapping Agent single device
  • Multicast PIM with multiple mapping-agents
• Candidate RPs: These are routers that wish to act as RPs. They send announcements to the mapping agents, indicating their willingness to serve specific multicast groups.

Candidate RPs send their RP-announce messages to a well-known multicast address. Mapping Agents receive these announcements and create a consolidated RP-to-group mapping. The Mapping Agents then multicast this mapping to all PIM routers using another well-known multicast address.

AutoRP is a mechanism to automate the process of RP discovery and distribution in PIM multicast networks, enhancing efficiency, reducing manual configuration, and improving network resilience.

Links:

https://networklessons.com/cisco/ccie-routing-switching/multicast-ip-pim-auto-rp