Huawei Updated H12-821_V1.0 Exam Questions and Answers by clover

This statement is false because IGMPv2 improves upon IGMPv1 by introducing the Leave Group message .

In IGMPv1 , members leave silently, and the router waits for the timeout.

In IGMPv2 , a host sends a Leave Group message, prompting the router to send a Group-Specific Query to determine if other members are still present. If no responses are received, the group is pruned before timeout.

Reference from Huawei HCIP-Datacom-Core Technology Study Guide:

“IGMPv2 allows group members to actively send Leave messages, reducing unnecessary forwarding delays. This improves efficiency over IGMPv1.”

(Chapter: Multicast Protocols – Section: IGMP Versions)

 MQC and PBR

MQC (Modular QoS Command-Line Interface) : Applied to interfaces for classifying and controlling traffic.

PBR (Policy-Based Routing) : Used to influence packet forwarding based on policies rather than traditional routing tables.

Both MQC and PBR can be configured on device interfaces to filter incoming/outgoing packets or control their forwarding paths.

 HCIP-Datacom-Core Reference

The use of MQC and PBR on device interfaces is elaborated in the QoS and routing control chapters​​.

Routing Entries in PIM

(S, G) entries : Represent the shortest path tree (SPT) from a specific source ( S ) to a specific multicast group ( G ). These entries are created after data packets are transmitted directly from the source to the receivers.

(S, G) entries are used in both PIM-DM and PIM-SM modes.

PIM-DM and PIM-SM Modes

In PIM-DM , multicast traffic is initially flooded throughout the network and pruned where no receivers exist. (S, G) entries represent source-specific paths created after the flooding stage.

In PIM-SM , multicast traffic initially flows through a shared tree, but (S, G) entries are created when the network switches to the SPT for more efficient forwarding.

HCIP-Datacom-Core Reference

The functionality and application of (S, G) routing entries are detailed in multicast and PIM configuration chapters​​.