Huawei Certified Network Professional – Routing and Switching v2 (HCNP-RS) — Question 16

How does an IGMP router maintain group memberships on the network? (Choose two.)

Answer options

• A. The router maintains a timer for each group membership. If the router receives a Report message from a receiver host, it refreshes the timer of the group membership of this host; if the router does not receive any Report message from a receiver host before the timer expires, it deletes the group membership of this host.
• B. The router periodically sends Query messages. After a receiver host receives the Query message, the receiver host sends a Report message.
• C. A receiver host periodically sends a Report message.
• D. The router deletes a group membership only when it receives a Leave message for this group.

Correct answer: A, B

Explanation

Option A is correct because the router uses timers to manage group memberships and relies on Report messages to keep them active. Option B is also correct as it describes the router's method of soliciting responses from hosts to maintain awareness of group memberships. Options C and D are incorrect because they do not accurately describe the primary mechanisms IGMP routers use to manage memberships.