200-301 Question 111
Select 3A network administrator is configuring multicast on a network to support video streaming services. They decide to use Protocol Independent Multicast (PIM) in Sparse Mode (PIM-SM). Which of the following statements about PIM-SM operation are correct?
- A
PIM-SM uses a Rendezvous Point (RP) to initially manage multicast group memberships.
- B
PIM-SM floods multicast traffic to all routers in the network regardless of interest.
- C
PIM-SM requires routers to explicitly join multicast groups to receive traffic.
- D
PIM-SM can switch from a shared tree to a source-specific tree for optimized traffic delivery.
- E
PIM-SM operates only in IPv4 networks and does not support IPv6.
Show answer and explanation
Correct answers: A, C, D
Explanation
PIM-SM is a widely used multicast routing protocol that ensures efficient traffic delivery by using a Rendezvous Point (RP) to manage group memberships and transitioning to source-specific trees when necessary. It operates on both IPv4 and IPv6 networks and avoids unnecessary flooding by requiring explicit joins from routers that want to receive multicast traffic.
- A. Correct.
Correct. PIM-SM uses an RP as a central point for managing initial multicast group traffic, ensuring efficient delivery.
- B. Incorrect.
Incorrect. PIM-SM does not flood traffic to all routers; instead, it sends traffic only to routers that explicitly join multicast groups.
- C. Correct.
Correct. PIM-SM requires routers to explicitly join multicast groups by sending Join messages, ensuring traffic is delivered only where needed.
- D. Correct.
Correct. PIM-SM can optimize traffic delivery by switching from a shared tree (using the RP) to a source-specific tree (direct path to the source).
- E. Incorrect.
Incorrect. PIM-SM supports both IPv4 and IPv6 networks, making it versatile for various network environments.