Helping Hand Questions for H12-821_V1.0

RPF (Reverse Path Forwarding) checks are used to prevent multicast loops. An RPF check uses the unicast routing table (or multicast static routes , if configured) to determine the correct incoming interface for a multicast packet.

Multicast protocols like PIM use the RPF mechanism , and the unicast routing table is the primary reference.

Multicast dynamic routing protocols do not maintain their own separate tables for RPF by default.

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

“RPF checks are performed using the unicast routing table or multicast static routes. The interface through which the multicast source is reachable is considered valid for RPF.”

(Chapter: Multicast – Section: RPF Principle)

ARP spoofing is a Layer 2 attack, as it targets ARP tables in switches or end devices. All other attacks, including IP spoofing, ICMP attacks, and Smurf attacks, are network layer (Layer 3) attacks ​.

RSTP improves convergence by introducing changes to the BPDU handling mechanism and port roles. However, RSTP does not rely on a fixed timeout of four Hello intervals for negotiation failure. Instead, RSTP uses a more dynamic mechanism to detect topology changes. The other options describe valid RSTP improvements ​.

Comprehensive and Detailed In-Depth Explanation:

A. TRUE → EBGP-learned routes can be advertised to both IBGP and EBGP peers .

B. FALSE → BGP uses incremental updates , meaning it only advertises changed routes , not all routes.

C. TRUE → BGP advertises only the best path to prevent unnecessary routing information.

D. TRUE → IBGP split-horizon rule : Routes learned from IBGP peers are not re-advertised to other IBGP peers (to prevent loops).

???? Reference: Huawei HCIA-Datacom Study Guide, BGP Route Advertisement and Split-Horizon Rule.