Refer to the exhibit.
A tunnel is configured between R3 to R4 sourced with their loopback interfaces. The ip pim sparsedense mode command is configured on the tunnel interfaces and multicast-routing is enabled on R3
and R4. The IP backbone is not configured for multicast routing.
The RPF check has failed toward the multicast source.
Which two conditions could have caused the failure? (Choose two.)
A.
The route back to the RP is through a different interface than tunnel 0.
B.
The backbone devices can only route unicast traffic.
C.
The route back to the RP is through the same tunnel interface.
D.
A static route that points the RP to GigabitEthernet1/0 is configured.
•For a successful RPF verification of multicast traffic flowing over the shared tree (*,G) from RP,
an ip mroute rp-address nexthop command needs to be configured for the RP address, that points
to the tunnel interface.
A very similar scenario can be found at the reference link below:
Reference. http://www.cisco.com/c/en/us/support/docs/ip/ip-multicast/43584-mcast-over-gre.html