CCNP Practice Question: Which two statements about PIM sparse mode…

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  PIM-SM uses a pull model where receivers explicitly join the multicast group.

  Why this is correct

  Correct because PIM-SM requires receivers to send IGMP joins, which trigger PIM joins toward the RP, pulling traffic only where needed.

• ✓

  In PIM-SM, the rendezvous point (RP) is the root of the shared tree.

  Why this is correct

  Correct because the RP acts as the meeting point for sources and receivers, and all shared tree (*,G) traffic flows through the RP.

• ✗

  PIM-SM automatically switches to the shortest path tree (SPT) immediately after the first multicast packet is received.

  Why it's wrong here

  Incorrect because the SPT switchover occurs after the first packet is received via the shared tree, not immediately upon the first packet; there is a brief window where the shared tree is used.

• ✗

  PIM-SM requires all routers in the domain to be configured with the same RP address.

  Why it's wrong here

  Incorrect because while the RP must be known to all routers, it can be learned dynamically via Auto-RP or BSR, not necessarily statically configured on every router.

• ✗

  PIM-SM supports only one RP per multicast group.

  Why it's wrong here

  Incorrect because a group can have multiple RPs for redundancy, though only one is active at a time; anycast RP is a common technique.