Which two statements about BIDIR-PIM are true? (Choose two)
A. It uses implicit join messages to signal membership.
B. It is designed to support one-to-many applications within a PIM domain.
C. It uses (*, G) multicast routing entries to make forwarding decisions.
D. It uses a designated forwarder to maintain a loop-free SPT.
E. Traffic can be passed downstream from the shared tree toward the RP.
C & E are the right answer. BIDIR-PIM doesn’t use SPT (source path tree) it uses shared trees instead.
https://www.cisco.com/c/dam/en/us/products/collateral/ios-nx-os-software/multicast-enterprise/prod_white_paper0900aecd80310db2.pdf
Page 3.
Because Bidir PIM uses only shared trees for traffic distribution, this protocol needs a mechanism
to get traffic from the sources to the rendezvous point. The designated forwarder provides that
mechanism (Figure 3)
C D is correct. RP is always upstream..
https://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/fsbidir.html
Didn’t want to believe it, but yes, you are right.
C D