Question 340
An enterprise network designer recommends: Run supported PIM sparse-mode and establish receiver-driven join state. Which situation most clearly calls for this action?
Explanation
Correct Answer
This case requires the Sparse-mode joins action. Routers build multicast distribution branches in response to explicit joins.
Incorrect Answers
This other case would be better matched to Use a PIM SSM (S,G) join toward the known source. Multicast forwarding can follow the source tree without an ASM rendezvous point.
This other case would be better matched to Use PIM Join/Prune behavior to withdraw unneeded branch state upstream. Upstream routers can stop sending traffic to a branch with no interested receivers.
This other case would be better matched to Allow the designated source-side router to register the source with the RP according to PIM-SM behavior. The RP learns the active source and can connect it to interested shared-tree receivers.