Free Huawei H12-821_V1.0 Practice Exam with Questions & Answers | Set: 2

Comprehensive and Detailed In-Depth Explanation:

IP Prefix lists are used to filter routes based on prefix and mask length .

The optional parameters include:

Index of the prefix list → Specifies priority/order (Optional).

Shortest mask length to be matched → Defines the minimum subnet mask (Optional).

Longest mask length to be matched → Defines the maximum subnet mask (Optional).

Mask length (D) is mandatory because it specifies the exact prefix length being matched.

???? Reference: Huawei HCIA-Datacom Study Guide, Configuring Prefix Lists for Route Filtering.

A stateful inspection firewall tracks the state of active connections. If a packet matches an existing session in the firewall ' s state table, it is allowed to pass. The diagram indicates that the TCP packet matches the session state, so the firewall forwards it ​.

By default, Huawei firewalls create security zones named untrust , dmz , trust , and local . These zones facilitate security policies for inbound, outbound, and inter-zone traffic control ​.

 OSPF Authentication Overview

OSPF supports three authentication modes:

Null Authentication : No authentication (default).

Plaintext Authentication : Uses clear-text passwords.

MD5 Authentication : Secure cryptographic authentication.

 Interface-Level Priority

When both interface-level and area-level authentication are configured, OSPF prioritizes interface-level authentication . This ensures that interface-specific security overrides area-wide configurations for greater granularity and security.

 HCIP-Datacom-Core Reference

OSPF authentication hierarchy and configurations are detailed in the OSPF security configuration chapter​.

Comprehensive and Detailed In-Depth Explanation:

Spanning Tree Protocol (STP) has long convergence times due to Listening and Learning states .

Rapid Spanning Tree Protocol (RSTP) introduces:

Proposal/Agreement (P/A) mechanism → Allows ports to quickly transition to Forwarding state without waiting.

This mechanism significantly reduces convergence time in a switched network .

Since RSTP does use the P/A mechanism to accelerate port forwarding, the statement is true .

???? Reference: Huawei HCIA-Datacom Study Guide, STP vs. RSTP and P/A Mechanism.

The LS age field in OSPF LSAs (Link State Advertisements) is measured in seconds and increments over time in the Link State Database (LSDB). If the LS age reaches the LSRefreshTime (30 minutes), the router that originated the LSA must regenerate it to keep the LSA valid in the network. Options C and B are incorrect since LS age does not decrease, and only the originator regenerates LSAs ​.

Comprehensive and Detailed In-Depth Explanation:

VRRP (Virtual Router Redundancy Protocol) HSB (Hot Standby Backup) mode ensures high availability for WLAN access controllers (ACs) .

A. FALSE → The default VRRP priority is 100 , but a higher value (not smaller) means a higher priority .

B. TRUE → The VRID (Virtual Router Identifier) must be the same on both master and backup ACs .

C. TRUE → The virtual IP address must match for seamless failover.

D. FALSE → The default VRRP advertisement interval is 1 second . However, this statement is false because the context suggests an incorrect assumption about configurability .

???? Reference: Huawei HCIA-Datacom Study Guide, VRRP in WLAN Deployments.

IGMPv1 supports general queries but does not define a Leave message. IGMPv2 introduces the Leave message type, which allows hosts to notify routers when they wish to leave a multicast group, improving efficiency. These distinctions align with the functionality of IGMP versions ​.