This object indicates how the RP was learnt, 'static' means
static (2) indicates entry was learnt from local
configuration.
bsr (3) indicates entry was learnt from BSR RP discovery
protocol.
embedded (4) indicates entry was learnt from Embedded-RP
mechanism where the RP-Address is embedded in the Multicast
Group address.
autorp (5) indicates entry was learnt from
Auto-Rendezvous-Point protocol, a Cisco proprietary protocol
to dynamically distribute Group to RP mappings within an
autonomous system.