Huawei H12-821_V1.0 Exam With Confidence Using Practice Dumps

Comprehensive and Detailed Step-by-Step Explanation:

OSPF State Machine:

OSPF adjacency progresses through several states: Down > Init > 2-Way > ExStart > Exchange > Loading > Full.

The 2-Way state indicates that routers have exchanged Hello packets but are not forming full adjacencies.

Possible Causes for Staying in the 2-Way State:

Hello Time Values Are Different (A): Mismatched Hello/Dead intervals prevent adjacency establishment.

Area IDs Are Different (B): OSPF routers must belong to the same area to establish adjacency.

Router IDs Conflict (C): While Router ID conflicts cause other issues, they do not result in the 2-Way state.

N-bit and E-bit Are the Same (D): Matching N-bit/E-bit values are normal and do not cause problems.

References:

HCIA-Datacom Study Guide, Chapter: OSPF Adjacency Establishment

Huawei OSPF Neighbor State Analysis

LS Ack (Link State Acknowledgment) packets are used to acknowledge received LSAs and do not contain complete LSA information. Instead, they contain only the headers of LSAs being acknowledged. This contrasts with LS Update packets, which carry full LSA details. The misunderstanding of LS Ack functionality makes this statement false ​.

If VRRP is not configured to track uplink interfaces, a failure in the master device's uplink or link will not trigger a switchover, resulting in a traffic blackhole. The VRRP mechanism relies on interface tracking to monitor connectivity and ensure role transitions upon faults. Without this configuration, no failover occurs, and traffic directed toward the master device is lost ​.