Multicast using Anycast RP with Auto-RP and BSR
In a multicast environment, it is possible to employ the use of anycast RP in conjunction with mechanisms such as AutoRP and BSR.
However, it requires some additional configuration to make them work together seamlessly.
Initially you must configure the Anycast RP on all RPs sharing the same IP address as well as MSDP between all Anycast RPs to share multicast source information.
Then, you can configure an Auto-RP and mapping agent functionality on one or more designated routers. The mapping agent listens for RP-announce messages and selects the best RP for each multicast group. It then advertises this information using RP-discovery messages. Make sure to configure the Anycast RP IP address as the RP in the Auto-RP configuration. This way, the routers in the PIM domain will learn about the Anycast RP through Auto-RP messages.
For BSR configurations, the idea is similar. Configure Anycast RP and MSDP as in this lesson. You can then configure PIM-SM on all routers within the PIM domain and enable BSR on one or more routers. This will allow the routers to automatically discover and select the best RP for each multicast group based on the BSR messages. Configure the Anycast RP IP address in the BSR candidate-RP configuration and a priority value. This will ensure that the routers in the PIM domain will learn about the Anycast RP through BSR messages.
Links:
https://networklessons.com/multicast/multicast-anycast-rp-configuration-cisco-ios
https://networklessons.com/multicast/multicast-ip-pim-auto-rp