H12-891_V1.0 Exam Dumps - Huawei HCIE-Datacom Questions and Answers

BGP EVPN Route Types in VXLAN:

BGP EVPN Type 2 Route (MAC/IP Advertisement Route)

Used for host reachability advertisement.

Carries MAC and IP address information of endpoints.

Does not carry an IP Prefix field (Type 5 routes handle prefixes).

Correct Explanation of Answer Choices:✅ IP Address (B) is included – Used for host mobility and reachability.✅ L3VNI (C) is included – Used for Layer 3 VXLAN routing.✅ L2VNI (D) is included – Used for Layer 2 VXLAN bridging.❌ IP Prefix (A) is not included in Type 2 routes – It is part of EVPN Type 5 routes for prefix advertisement.

Reference from Huawei HCIE-Datacom Documentation:

Huawei VXLAN BGP EVPN Configuration Guide – Type 2 vs. Type 5 Routes

HCIE-Datacom Training Material – VXLAN Overlay Networks and BGP EVPN

Comprehensive and Detailed In-Depth Explanation:

During a network migration test, it is crucial not only to verify that the network itself is functioning correctly but also to ensure that upper-layer application services are running properly on the newly migrated network. Migration testing aims to confirm that the transition has not disrupted service functionality.

Option A and C focus solely on network performance, which is necessary but insufficient.

Option B refers to command outputs, which are technical checks and do not guarantee service continuity.

Option D correctly identifies that successful migration is indicated by proper operation of upper-layer application services, as the primary purpose of a network is to support these applications.

Understanding SSH Authentication and Key Exchange

???? What Happens When an SSH Client Connects to a Server?

1️⃣ Key Exchange Phase (KEX)

Even if only password authentication is used, SSH still performs key exchange.

The server and client negotiate encryption keys using algorithms like Diffie-Hellman (DH).

2️⃣ User Authentication Phase

After encryption keys are exchanged, the user authenticates using a username and password.

Why is the Answer FALSE?

❌ Even with password authentication, SSH still performs key exchange to establish an encrypted session.

✅ The SSH session is always encrypted using cryptographic keys generated during KEX.

Real-World Application:

Secure Remote Access: Protects login credentials from MITM (Man-in-the-Middle) attacks.

Cloud & Datacenter Networks: Ensures secure SSH connections across remote infrastructure.

✅ Reference: Huawei HCIE-Datacom Guide – SSH Key Exchange and Authentication

Forwarding Equivalence Class (FEC) is a key concept in MPLS (Multiprotocol Label Switching), where packets with the same forwarding characteristics are grouped into an FEC and assigned a label.

Correct Answers (Cannot be Used for FEC Allocation):

A. Fragment Offset – Incorrect as an FEC allocation standard

Fragment offset is used for reassembling fragmented IP packets at the receiver side.

It is not relevant for MPLS label assignment.

B. Application Protocol – Incorrect as an FEC allocation standard

MPLS does not classify packets based on application-layer protocols (e.g., HTTP, FTP).

It works mainly at Layer 2 and Layer 3.

Incorrect Answers (Valid FEC Allocation Standards):

C. Destination Address – Valid FEC allocation criterion

One of the most common MPLS FEC classifications.

Packets with the same destination are grouped into the same FEC.

D. Class of Service (CoS) – Valid FEC allocation criterion

MPLS uses CoS-based traffic classification (e.g., Exp bits in MPLS headers).

Different CoS levels can be mapped to different labels.

Reference from Huawei HCIE-Datacom Documentation:

Huawei MPLS Technology Guide – FEC and Label Assignment

HCIE-Datacom MPLS VPN Configuration Guide

EVPN Route Types:

Type 1 (MAC/IP Advertisement Route): Advertises host MAC and IP information — used.

Type 2 (MAC/IP Advertisement Route): Advertises MAC + IP binding for end hosts — used.

Type 3 (Inclusive Multicast Ethernet Tag Route): Used to advertise VXLAN multicast group info — used.

Type 4 (Ethernet Segment Route): Used in multi-homing scenarios, especially in DC (data center) environments, to coordinate DF election — typically not used in campus VXLAN.

So in campus virtualized networks, which are often single-homed, Type 4 is not required.

Correct answer: C. Type 4

Comprehensive and Detailed In-Depth Explanation:

Blackhole MAC address configuration is a security feature that helps protect a network from MAC address spoofing or attacks involving untrusted MAC addresses. When you configure a MAC address as a blackhole MAC address, any packet received with that address as the source or destination will be immediately discarded by the device.

This feature is useful in scenarios where certain MAC addresses are identified as malicious or untrusted. By adding these MAC addresses to the blackhole list, the device effectively blocks communication involving these addresses, thereby mitigating security risks.

Huawei Switch Deployment Methods in CloudCampus

✅ A. DHCP Option 148 – Used for automatic device registration in iMaster NCE-Campus.

✅ B. CLI (Command-Line Interface) – Traditional manual configuration method using the command-line interface.

✅ C. Web Interface – Web GUI-based configuration for easy management.

✅ D. Huawei Registration Center – Cloud-based automatic registration and provisioning for plug-and-play deployment.

Reference from Huawei HCIE-Datacom Documentation:

Huawei CloudCampus Deployment Guide – Device Onboarding Methods

HCIE-Datacom Training Material – Zero-Touch Deployment (ZTP) in CloudCampus

Comprehensive and Detailed In-Depth Explanation:

The traceroute output shows that the path from R1 to the destination 172.17.1.5 is looping. After reaching the IP 10.1.13.1, the path goes back to 10.1.12.2, repeating the previous hops. This indicates a routing loop, where R1 continuously forwards packets through a circular path, never reaching the destination. Routing loops typically occur due to inconsistent or incorrect routing table entries, often because of routing protocol misconfigurations.

Comprehensive and Detailed Explanation:

The OSPF error output shows:

✔ Hello timer mismatch (1 error) → Hello intervals must match for adjacency formation (A) ✅

✔ No Netmask mismatch errors → Subnet masks are consistent, so option C is incorrect ❌

✔ No Extern option mismatch → No evidence of area type inconsistency (option D) ❌

✔ If area IDs were mismatched, adjacency would not form (option B is correct) ✅

Thus, the correct answers are A and B.

???? Reference: Huawei HCIE Datacom – OSPF Troubleshooting