Free Huawei H12-891_V1.0 Practice Exam with Questions & Answers | Set: 5

Understanding Route Reflectors (RRs) in Huawei SD-WAN

In Huawei’sSD-WAN Solution, BGPRoute Reflectors (RRs)are used toreduce the number of BGP peer relationshipsand optimize routing scalability.

????Key Functions of an RR in SD-WAN:

CentralizesBGP route distributionin large-scale SD-WAN networks.

Reducesfull-mesh BGP peering complexity.

Improves network scalabilityand convergence time.

Analysis of Each Deployment Mode:

✅B. Independent deployment of the RR

Correct:The RR is deployed as astandalonedevice, independent of the SD-WAN hub site.

Best for large-scale SD-WAN deploymentsrequiring dedicated route control.

✅C. Co-deployment of the RR and hub site

Correct:The RR is co-located with the SD-WANhub site, reducing infrastructure overhead.

Best for mid-sized SD-WAN deploymentswhere thehub and RR functions can be combined.

✅D. Partially independent deployment of the RR

Correct:The RR ispartially separatedfrom the hub but still shares some resources.

Provides a balance between full independence and co-location.

❌A. Multi-area deployment of the RR (Incorrect Choice)

Multi-area RR deployment isnot a common Huawei SD-WAN practice.

Huaweidoes not require separate RRs per area, as SD-WAN is based oncentralized policy-based routing.

Real-World Application:

Large Enterprise SD-WAN:Usesindependent RRsto optimizeglobal network routing.

Service Provider SD-WAN:Usesco-deployed RRsto reduce infrastructure costs while maintainingroute scalability.

✅Reference:Huawei HCIE-Datacom Guide – BGP Route Reflectors in SD-WAN Architecture

Comprehensive and Detailed In-Depth Explanation:

AnHTTP responsefrom the server to the client typically includes the following components:

Protocol version (C):Specifies the HTTP version used (e.g., HTTP/1.1).

Status code (B):Indicates the response result (e.g., 200 for OK, 404 for Not Found).

Reason phrase (A):A textual description associated with the status code (e.g., "OK", "Not Found").

Headers and Body:Contain additional information and the actual response content.

URI (D):TheUniform Resource Identifieris part of theHTTP requestand not theHTTP response. Therefore,Dis the correct answer.

Understanding Inter-AS MPLS L3VPN Option C

????MPLS L3VPN provides Layer 3 VPN services over an MPLS backboneby using BGP to exchange VPN routes.

????Inter-AS MPLS L3VPN Option C (Carrier-to-Carrier Model) works as follows:

ASBRs (Autonomous System Boundary Routers) exchangeVPNv4 routes using MP-BGP.

ASBRsdo NOT store VPN routing tables. Instead, theyadvertise labeled IPv4 routesto enable inter-AS forwarding.

How ASBR-PE2 Enables Inter-AS Communication?

✅VPNv4 Address Family (Answer A - Required)

Used to exchangeMPLS VPN routes between PE routers.

MP-BGP (Multiprotocol BGP) exchanges VPNv4 prefixesbetween ASBR-PE1 and ASBR-PE2.

✅Unicast BGP Address Family (Answer D - Required)

Required to exchangeIPv4 labeled routesbetween ASBRs.

EnsuresMPLS label forwarding between AS100 and AS200.

❌BGP-LS Address Family (Answer B - Not Required)

BGP-LS (BGP Link-State) is used for SDN controllersto learn topology information.

It isnot required for Inter-AS MPLS L3VPN.

❌VPN Instance Unicast Address Family (Answer C - Not Required)

This is used forPE-CE communicationbut isnot required between ASBRs.

Why is the Answer A, D?

✅VPNv4 routes enable inter-AS VPN communication.

✅IPv4 unicast routes are required for ASBR-PE2 to forward packets across AS boundaries.

Real-World Application:

Service Provider Networks:Used incarrier-to-carrier MPLS VPN deployments.

Enterprise WAN Interconnection:Enablesmulti-AS MPLS VPN connectivityfor large enterprises.

✅Reference:Huawei HCIE-Datacom Guide – Inter-AS MPLS L3VPN Option C (Carrier-to-Carrier Model)

There arethree standard inter-AS MPLS VPN options, as per RFC 4364:

Option A (Back-to-Back VRF):

VRFs are directly connected between ASBRs using routing exchange (like static/BGP).

No label switching between ASs —no MPLS label neededbetween ASs.

Option B (EBGP Label Exchange):

ASBRs exchange labeled VPNv4 routes via EBGP.

One MPLS label is required —MPLS forwarding across AS boundaryis used.

Option C (End-to-End LSP):

Full end-to-end LSP is created across ASs.

MPLS labels are definitely usedend-to-end, even between ASs.

Option D (Commonly vendor-specific extensions based on Option B/C):

Similar to Option C —requires MPLS labels.

So:

B. Option B— needs MPLS label✅

D. Option D— also needs MPLS label✅

A. Option A—no MPLS label❌

C. Option C— also uses MPLS label✅, but not listed as an answer option in this question format (should have been).

Assuming valid options areA, B, D, the correct ones needing MPLS labels are:

Correct answers: B, D

Huawei’sOPS (Open Programmability System)enables programmable interactions with devices through Python-based templates. In Huawei's OPS Python environment:

The classOPSConnectionis used to manage device interactions.

It includes methods like:

get()

post(self, uri, req_data)→ used tocreate resources

put(),delete(), etc.

This aligns with RESTful API semantics, and the post() method in the context given is used correctly.

Correct answer: A. TRUE

OSPFv3 (used for IPv6) usesIPv6 multicast addressesfor communication between routers:

FF02::5— All OSPF routers.

FF02::6— All OSPF Designated Routers (DRs) and Backup Designated Routers (BDRs).

FF08::x— These are used for organization-local scope, which isnotapplicable to standard OSPFv3 operation.

Therefore:

C. All OSPF routers use FF02::5— Correct

D. The DR uses FF02::6— Correct

A and B (FF08::x)— Incorrect. These addresses are not used by OSPFv3 in this context.

Correct answers: C and D

Understanding HTTP/1.1 Response Structure

????What is an HTTP Response?

The response issent from the server to the client after processing an HTTP request.

The structure follows astandardized format:

Elements of an HTTP/1.1 Response:

✅A. Status Line→ Containsprotocol version, status code, and reason phrase.

✅B. Response Body→ ContainsHTML, JSON, XML, or other content.

✅C. Response Header→ Providesmetadata about the response(e.g., Content-Type, Server).

✅D. Empty Line→ Ablank line separates headers from the response body.

Example of an HTTP/1.1 Response:

HTTP/1.1 200 OK

Date: Sat, 08 Mar 2025 14:00:00 GMT

Server: Apache/2.4.41 (Ubuntu)

Content-Type: text/html; charset=UTF-8

<html>

<body>

<h1>Welcome to Huawei Datacom</h1>

</body>

</html>

Why is the Answer A, B, C, D?

✅An HTTP response includes a status line, headers, an empty line, and a response body.

Real-World Application:

Web Application Debugging:Helps developersanalyze server responses.

API Security:Validatesresponse headers to prevent injection attacks.

✅Reference:Huawei HCIE-Datacom Guide – HTTP Protocol and Response Headers

Huawei Open Programmability System (OPS) and Scripting Support

HuaweiOPS (Open Programmability System)enables network automation usingscript-based programmingfordevice management and configuration.

✅Python is the primary language integrated into Huawei OPS.

Python scripts can automate device configurations, monitoring, and troubleshooting.

OPS supports Python libraries for interacting with network APIs and CLI commands.

Used for Huawei CloudCampus, SDN, and Datacom devices.

A screenshot of a computer AI-generated content may be incorrect.

InOSPFv3, each LSA type has adefined flooding scope:

Link-LSA (Type 8)

Advertisedonly on the local link

Contains router’s link-local address and prefixes

Scope:Within the local link scope✅

AS-External-LSA (Type 5)

Used to advertiseexternal routes from outside the AS

Flooded across theentire autonomous system, except stub/NSSA areas

Scope:Within an AS✅

Network-LSA (Type 2)

Generated by theDesignated Router (DR)

Describes all routers on a broadcast or NBMA segment

Floodedwithin the originating area

Scope:Within an area✅

Correct Mappings:

Link LSA→Within the local link scope

AS-External-LSA→Within an AS

Network-LSA→Within an area

Understanding User Authentication Points in a Network

Authentication pointscan be deployed at different network layersbased on security and scalability needs:

✅Access Layer Authentication:

Ensureshigh security & granular control(user-level authentication).

Preferred inhigh-security enterprise networks.

✅Aggregation or Core Layer Authentication:

Reduces authentication overheadbutprovides less granular control.

Suitable forlarge-scale networkswhere authentication load needs to be balanced.

Analysis of the Answer Choices:

✅A. Deploying user authentication points at the access layer achieves granular permission management and high network security.

Correct:Providesfine-grained control per userand prevents unauthorized access.

✅B. Moving user authentication points from the access layer to the aggregation or core layer greatly reduces the number of user authentication points, thereby effectively mitigating the pressure on the AAA server.

Correct:Fewer authentication points meanless load on the AAA server.

✅C. Deploying user authentication points at the access layer has both advantages and disadvantages when compared to doing so at the aggregation or core layer. Policy association can be applied if user authentication points are deployed at the access layer.

Correct:Policy-based authentication isbest applied at the access layerforgranular control.

❌D. When user authentication points are moved from the access layer to the aggregation layer, MAC address authentication for users may fail.

Incorrect:MAC authentication worksat both layers, butpolicy adjustmentsmay be needed.

✅Reference:Huawei HCIE-Datacom Guide – User Authentication Strategies in Enterprise Networks