Auto-rp or BSR

BSR uses 224.0.0.13 for BSR announcements (from BSR to all pim routers) and unicast for RP announcements (from RP to BSR router).

Auto-RP uses 224.0.1.39 for RP announcements (from RP to MA) and 224.0.1.40 for MA announcements (from MA to all pim routers).

On hub-n-spoke networks, when auto-rp announcements must pass between the spokes, you cannot use "ip nbma-mode", because this works only in sparse mode (and announcements are in dense). You have to use BSR or create a pim-enabled tunnel between the spokes.


BSR uses only sparse-mode. When using BSR & "sparse-dense-mode", you might need to add "no ip pim dm-fallback" to prevent groups without an RP from operating in dense mode.

Auto-RP uses dense-mode for its own announcements, so you have to use one of the following on each pim enabled router:
1) "sparse-dense-mode"
2) "sparse-mode" & "ip pim auto-rp listener"


In BSR we cannot define neither the interval of BSR announcements, nor the scope of them (we can define the RP announcements). In Auto-RP we can define all of them.

In Auto-RP we cannot define the priority of each RP. The RP with the higher ip address wins. In BSR we can define the priority of each RP.

To filter BSR announcements from entering/leaving your network, you can use "ip pim bsr-border".
To filter Auto-RP announcements entering/leaving your network, you can use "ip multicast boundary ACL in/out filter-autorp".