Important Huawei H12-891_V1.0 Exam Questions

Answer: A, B, D

Explanation:

Understanding 'Two-City Three-Center' Networking

What is 'Two-City Three-Center' Networking?

A high-availability disaster recovery (DR) solution used by financial institutions, government, and enterprise networks.

'Two cities' Indicates that data centers are deployed in two different locations for redundancy.

'Three centers' Includes two active data centers + one remote disaster recovery center.

Bearer WAN Layers in 'Two-City Three-Center' Networks

A. Core Layer

Provides high-speed backbone connectivity between different data centers.

Uses high-capacity routers and optical links for long-distance communication.

B. Aggregation Layer

Connects access sites to the core network.

Aggregates traffic from branch offices, remote sites, and smaller data centers.

D. Access Layer

Connects end-users, remote branches, and applications to the WAN.

Uses CE (Customer Edge) routers and firewalls to ensure secure access.

C. Control Layer (Incorrect Choice)

The control plane exists in networking, but it is not a physical bearer WAN layer.

The control layer is a logical function, not a network topology layer.

Real-World Application:

Banking Networks: Ensures that core banking applications remain available even in case of a disaster.

Government Data Centers: Enables cross-city data replication for public services.

Reference: Huawei HCIE-Datacom Guide -- 'Two-City Three-Center' Network Design

Answer: A, C, D

Explanation:

Analyzing the Routing Table Output:

The command display ipv6 routing-table protocol isis shows all IPv6 routes learned via IS-IS.

The output shows 'Summary Count: 6', meaning R1 has six IS-IS IPv6 routes.

Explanation of Correct Answers: A. R1 has six IS-IS IPv6 routes.

The 'Summary Count: 6' confirms that six IS-IS IPv6 routes exist in R1's routing table.

C. IS-IS IPv6 must have been enabled on GigabitEthernet0/0/1 of R1.

The interface GigabitEthernet0/0/1 is listed as the next-hop, meaning IS-IS IPv6 must be enabled on that interface.

D. R1 is not a Level-1 device.

The protocol is listed as 'ISIS-L2', indicating that R1 is an IS-IS Level-2 (backbone) router, not a Level-1 router.

Incorrect Answer B. R1 does not have IS-IS IPv6 routes.

Wrong! The output clearly shows six IS-IS IPv6 routes, proving this statement false.

Reference from Huawei HCIE-Datacom Documentation:

Huawei IPv6 Routing Protocols Guide -- IS-IS for IPv6

HCIE-Datacom Routing & Switching Training -- IS-IS L1 & L2 Operations

Huawei IS-IS Configuration Guide -- IPv6 Route Management

Answer: C

Explanation:

GRE (Generic Routing Encapsulation) supports encapsulation of many protocol types:

Supports IPv4 and IPv6 unicast encapsulation ---

Does not support IPv6 broadcast encapsulation. GRE doesn't natively handle multicast or broadcast IPv6 traffic well ---

It is a lightweight tunneling protocol and relatively easy to deploy, placing minimal overhead on devices ---

Correct answer: C. GRE can encapsulate IPv6 broadcast packets --- is incorrect.

Answer: A, B, C, D

Explanation:

802.1X Authentication Overview

802.1X is a port-based authentication mechanism used for secure network access control. It involves:

EAPoL (Extensible Authentication Protocol over LAN) communication between the client (supplicant) and the switch (authenticator).

RADIUS communication between the authenticator and the authentication server (AAA server).

A. 802.1X authentication uses EAPoL to exchange authentication information.

EAPoL (Extensible Authentication Protocol over LAN) is used to send authentication packets over Ethernet (IEEE 802.3) networks.

B. In EAP termination mode, the network device terminates EAP packets and re-encapsulates them into RADIUS.

The switch acts as an authentication proxy by terminating EAP sessions and converting authentication information into RADIUS format.

C. EAPoL is for wired (802.3), EAPoW is for wireless (802.11).

EAPoL (EAP over LAN) is used in wired Ethernet networks.

EAPoW (EAP over Wireless) is used in Wi-Fi (802.11) networks.

D. In EAP relay mode, EAP packets are encapsulated into RADIUS using EAPoR (EAP over RADIUS).

The switch does not terminate the EAP session but instead forwards EAP messages to the AAA server inside RADIUS packets.

Reference from Huawei HCIE-Datacom Documentation:

Huawei 802.1X Configuration Guide -- EAPoL, EAPoW, and EAPoR

HCIE-Datacom Training Material -- AAA Authentication Modes

Answer: C

Explanation:

Comprehensive and Detailed

SR Policies are dynamically computed and delivered by the SDN controller in an SR-MPLS or SRv6 network.

Correct Statements:

(A) NETCONF is used for delivering configurations like routing policies and service interfaces.

(B) BGP-LS (Link-State) is used to collect topology and compute SR Policies.

(D) BGP IPv6 SR Policy distributes SR policy attributes like color, headend, and endpoints.

Why Is (C) Incorrect?

(C) The controller does not use telemetry to deliver SID entries---telemetry is used for real-time monitoring, not path computation.

Reference: Huawei HCIE Datacom -- SR Policy and Controller-Based Path Computation