Pass the Huawei HCIE-Datacom H12-891_V1.0 Questions and answers with CertsForce

Comprehensive and Detailed Explanation:

✔gRPC supports four types of RPCs:

Unary RPC→ Client sendsonerequest, server respondsonce.

Server streaming RPC→ Server sendsmultiple responses.

Client streaming RPC→ Client sendsmultiple requests.

Bidirectional streaming RPC→Bothsides exchange multiple messages.

✔Why B and C Are Incorrect:

❌(B) Incorrect→ The method rpc dataPublish(stream serviceArgs) returns(stream serviceArgs) {} violates gRPC syntax.

❌(C) Incorrect→ rpc stream LotsOfGreetings(HelloRequest) returns (HelloResponse) {} containsincorrect stream positioning.

????Reference:Huawei HCIE Datacom – gRPC API and Streaming Mechanisms

InBGP/MPLS IP VPN, whenOSPF is used as the PE-CE routing protocol,Domain IDsare used to determine whether theOSPF routes imported into the VPN instancebelong to the same OSPF domain.

How Domain ID Works in OSPF and MPLS VPN:

Same Domain ID (OSPF Intra-domain routes)

If thePE router's Domain ID matches the OSPF Domain ID, routes aretreated as intra-area routes.

The routes retainOSPF attributeswhen redistributed into the VPN.

Different Domain ID (OSPF Inter-domain routes)

If theDomain ID does not match, routes aretreated as external routes (Type 3 or Type 5 LSAs).

The PE router redistributes these routes asOSPF external routes.

Example Huawei Configuration for Domain ID in OSPF VPN:

ospf 1 vpn-instance VPN1

domain-id 1.1.1.1

This ensuresconsistent OSPF route typeswhen exchanging routes between PE and CE.

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS VPN Configuration Guide – OSPF Domain ID in PE-CE Routing

HCIE-Datacom Study Material – OSPF & MPLS VPN Route Redistribution

Comprehensive and Detailed Explanation:

✔Fit APs require additional configurations before going online, such as:

AP authentication and onboardingthroughDHCP Option 148ormanual registration.

Firmware upgrade and provisioningfrom iMaster NCE-Campus.

Policy enforcementand VLAN assignment.

Since additional steps are required,Fit APs do not go online immediately, making the statementFALSE.

????Reference:Huawei HCIE Datacom – AP Registration and Authentication

Comprehensive and Detailed Explanation:

Inter-AS MPLS L3VPN Option BrequiresASBRs to exchange VPNv4 routesusingeBGPwith label information.

Analysis of Inter-AS VPN Solutions:

Option B uses eBGP to exchange labeled VPNv4 routes between ASBRs but does not require MPLS between ASBRs.

Option A does not exchange VPNv4 routes over ASBRs (uses IP routing instead).

Option C uses MP-BGP and requires full MPLS between ASBRs.

Since Option B requires ASBRs to exchange VPNv4 routes, the correct answer is B.

????Reference: Huawei HCIE Datacom – MPLS Inter-AS VPNs

Correct Order for HTTP Request Line:

1. Request Method (e.g., GET, POST)

2. URI (Uniform Resource Identifier) (e.g., /index.html)

3. Protocol Version (e.g., HTTP/1.1)

Request Method

URI

Protocol Version

Comprehensive and Detailed Explanation:

Structure of an HTTP Request Message

An HTTP request message consists of:

1️⃣Request Line → Specifies the request method, the target resource (URI), andthe HTTP version.

2️⃣Headers → Provides additional request details (e.g., Host, User-Agent).

3️⃣Body (optional) → Used in methods like POST for sending data.

Format of an HTTP Request Line:

GET /index.html HTTP/1.1

GET → Request method

/index.html → URI (resource being requested)

HTTP/1.1 → Protocol version

Why Other Fields Are Incorrect?

❌Status Code → This belongs to an HTTP response, not a request.

❌Mixing Headers into the Request Line → Headers should be placed separately after the request line.

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

In BGP, community attributes help control the advertisement scope of BGP routes. Here’s what each option means:

No_Export: This well-known community attribute prevents BGP routes from being advertised to external BGP (EBGP) peers. Routes with this attribute can still be advertised to internal BGP (IBGP) peers within the same AS. This ensures that the route remains within the originating AS.

No_Advertise: This attribute means that the route should not be advertised toanyBGP peer, whether internal or external.

Internet: Indicates that the route can be advertised to all BGP peers, both internal and external, with no restrictions.

No_Export_Subconfed: Similar to No_Export, but it also restricts advertisement to peers within a BGP confederation. It's more specific and not generally used just to keep routes inside one AS.

Therefore, the correct answer isB. No_Export, as it is the attribute that ensures BGP routes remain within the AS by not being sent to EBGP peers.

Comprehensive and Detailed In-Depth Explanation:

The correct configuration is qos car inbound cir 50000 pir 100000.

CIR (Committed Information Rate):The guaranteed minimum bandwidth, set to 50 Mbit/s (50000 kbps).

PIR (Peak Information Rate):The maximum allowable bandwidth, set to 100 Mbit/s (100000 kbps).

This configuration ensures that during peak hours, the minimum guaranteed bandwidth is 50 Mbit/s, while during off-peak hours, the bandwidth can increase to a maximum of 100 Mbit/s. The settings align with the carrier's requirements for dynamic bandwidth allocation based on network load.

Virtual Networks in Huawei CloudCampus Solution:

Virtual networks (VNs) aresegmented based on services(e.g., IoT, Guest Wi-Fi, Enterprise Wi-Fi).

Each VN has its ownrouting and forwarding instance(VRF).

Isolation Between Virtual Networks:

By default,different virtual networks are isolated.

If inter-VN communication is required, it must be manually configuredusingpolicy-based routing (PBR), inter-VRF routing, or firewall policies.

Reference from Huawei HCIE-Datacom Documentation:

Huawei CloudCampus Solution Guide – Virtual Networks and Segmentation

HCIE-Datacom Training Material – Policy-Based Inter-VN Communication

Comprehensive and Detailed In-Depth Explanation:

In the Label Distribution Protocol (LDP) session establishment process, theInitialization messageis sent by the initiator to propose parameters for the session. If the responder finds that the proposed parameters are not acceptable, it responds with anError Notification Message. This message indicates that the session could not be established due to incompatible or incorrect parameters.

TheError Notification Messagetypically includes details about why the session could not be established, such as parameter mismatch or unsupported features. If the parameters are acceptable, the responder would instead reply with aKeepalive Messageto maintain the session.