Multicast PIM Auto RP

Hello Deep

Routers will only play the role of a RP or an MA if they are statically configured as such. Specifically, to configure a router as a candidate RP and thus to have it announce itself as such, the following command must be present:

ip pim send-rp-announce

To configure a router as an MA the following command must be present:

ip pim send-rp-discovery

The above are configured on R1 and R2 respectively. R4 is not configured to announce itself as an RP so it will not do so. R4 does however recieve the information from the mapping agent because of the following command that is found on R3

ip pim autorp listener

This command allows the multicast traffic that reaches R3 to be flooded with dense mode, thus it will flood those packets to R4.

I hope this has been helpful!

Laz