Multicast PIM Bootstrap (BSR) election

In a multicast topology, BSR (Bootstrap) is a protocol that we use to automatically find the RP in our sparse mode network topology.

There can be only one active BSR in the network. BSR routers will listen for messages from other BSR routers, the BSR router with the highest priority will become the active BSR. The highest BSR priority is 255 (the higher the better). When the priority is the same then the router with the highest IP address will become the BSR.

This is in contrast to the way in which a Multicast PIM with multiple mapping-agents takes place when using Auto-RP.