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

Comprehensive and Detailed In-Depth Explanation:

After Portal authentication on a wireless network, the following parameters can be used for authorization:

free-rule (A): Allows traffic even before authentication.

UCL (B): User Control List, specifying user permissions.

ACL (D): Access Control List, defining permitted or denied traffic.

The IP address (C), however, is not used as an authorization parameter directly. Instead, IP addresses are typically assigned after successful authentication, and the control policies are applied based on user profiles or access lists.

Authentication Header (AH) in IPsec

The Authentication Header (AH) protocol is part of IPsec and provides authentication, integrity, and replay protection but does NOT provide encryption.

✅ B. AH provides data origin authentication.

Ensures that packets come from a trusted source using cryptographic signatures.

✅ C. AH provides anti-replay protection.

Uses sequence numbers to prevent attackers from replaying old packets.

✅ D. AH provides data integrity authentication.

Ensures data integrity by verifying that packets have not been tampered with during transmission.

❌ A. AH provides packet encryption – Incorrect!

AH does not encrypt packet contents. It only authenticates headers.

ESP (Encapsulating Security Payload) is used for encryption in IPsec.

Reference from Huawei HCIE-Datacom Documentation:

Huawei IPsec Configuration Guide – AH vs. ESP

HCIE-Datacom Training Material – IPsec Security Mechanisms

From the output:

Tunnel destination IP address: Clearly shown as destination 10.0.1.1 → ✅

Tunnel interface MTU: Shown as The Maximum Transmit Unit is 1500 → ✅

Tunnel interface IP: Shown as Internet Address is 20.1.1.2/24 → ✅

Tunnel source: Tunnel source 10.0.3.3 (LoopBack0) → Not 10.0.1.1 → ❌

Therefore:

A — Correct

B — Correct

C — Correct

D — Incorrect (confuses destination as source)

Correct answers: A, B, C

Option A: Correct — both terminal and interface security are important.

Option C: Correct — CAPWAP supports DTLS encryption for secure tunnel communication.

Option D: Correct — intranet security design considers both wired and wireless.

Option B: Incorrect — traffic suppression (such as broadcast suppression) is implemented using rate limiting or storm control, not by shutting down interfaces. Shutting down interfaces would disrupt legitimate traffic too.

Correct answer: B

SRv6 Instruction Naming Conventions

SRv6 (Segment Routing over IPv6) uses segment identifiers (SIDs) with specific functions, indicated by instruction keywords:

✅ A. T: Searches a specified routing table to forward packets.

T (Table Lookup) → Performs a lookup in a specified routing table and forwards packets accordingly.

❌ B. M: Searches a Layer 2 forwarding table for unicast forwarding.

Incorrect! SRv6 does not use M for Layer 2 unicast forwarding.

✅ C. V: Searches a VPN instance routing table to forward packets.

V (VPN Routing Table Lookup) → Performs a lookup in a VPN instance (VRF) table for forwarding.

✅ D. X: Forwards packets through one or a group of specified Layer 3 interfaces.

X (Cross-connect forwarding) → Forwards packets via a specified Layer 3 interface or group of interfaces.

Reference from Huawei HCIE-Datacom Documentation:

Huawei SRv6 Configuration Guide – SRv6 SID Naming and Instruction Set

HCIE-Datacom Study Material – Segment Routing over IPv6 (SRv6) Functionality

Understanding OSPF Neighbor States

OSPF (Open Shortest Path First) establishes neighbor relationships through several states:

1️⃣ Down: No Hello packets received.

2️⃣ Init: Router receives Hello packets but its own Router ID is missing in the received packets.

3️⃣ 2-Way: Routers see each other in Hello packets. (Stable state for non-DR/non-BDR routers).

4️⃣ ExStart: Routers start exchanging LSAs but may face MTU mismatches.

5️⃣ Exchange: Routers send Database Description (DBD) packets to synchronize link-state databases.

6️⃣ Loading: Routers exchange Link-State Requests (LSRs) & Updates (LSUs) to fully sync.

7️⃣ Full: Routers are fully synchronized.

Analysis of the Answer Choices

✅ A. For non-DR and non-BDR routers on an Ethernet link, the 2-Way state is acceptable.

Correct: Non-DR/Non-BDR routers remain in 2-Way state since they don’t need to form full adjacency.

✅ B. The Init state indicates that the router has received Hello packets from its neighbors, but the received Hello packets do not contain the OSPF RID of the receiving router.

Correct: If an OSPF router receives a Hello but does not see its own Router ID, it stays in the Init state.

✅ C. The ExStart state indicates that two neighbor routers have inconsistent MTUs or the same OSPF Router ID (RID).

Correct: If MTUs mismatch or RIDs conflict, the DBD exchange fails, causing routers to remain in ExStart state.

❌ D. The Attempt state indicates that the router does not send unicast Hello packets to configured neighbors.

Incorrect:

In Attempt state, routers send unicast Hello packets to manually configured neighbors (common in NBMA networks).

If no Hello responses are received, they remain in Attempt state, but they DO send Hellos.

Real-World Application

OSPF Troubleshooting: Identifying routers stuck in Init or ExStart states can point to MTU mismatches or neighbor misconfigurations.

NBMA Networks (Frame Relay, DMVPN): Manually configured neighbors may stay in Attempt state if Hello packets are lost.

✅ Reference: Huawei HCIE-Datacom Study Guide – OSPF Neighbor States & Troubleshooting

Before performing a network cutover (migration or upgrade), it is essential to collect baseline data to ensure that services operate normally before and after the change.

Importance of Pre-Cutover Information Collection:

Identifies Network Baseline – Helps compare pre-cutover and post-cutover performance.

Detects Hidden Issues – Ensures that no existing network issues interfere with the cutover process.

Prevents Service Interruptions – Ensures all dependent services are accounted for.

Provides Rollback Plan – If issues arise, administrators can restore previous configurations.

Reference from Huawei HCIE-Datacom Documentation:

Huawei Network Change Management Guide – Pre-Cutover & Post-Cutover Best Practices

HCIE-Datacom Training Material – Service Assurance & Risk Analysis

Comprehensive and Detailed In-Depth Explanation:

1. GRE Tunnel Configuration Details:

GRE (Generic Routing Encapsulation) is used to encapsulate packets for transmission between two endpoints.

The tunnel is created between R1 and R2:

R1 Tunnel IP: 10.1.1.1

R2 Tunnel IP: 10.3.1.1

Source IP of Tunnel: 10.0.12.1 (R1)

Destination IP of Tunnel: 10.0.12.2 (R2)

The command used: ping -a 10.1.1.1 10.3.1.1

Source IP (Inner IP): 10.1.1.1

Destination IP (Inner IP): 10.3.1.1

2. GRE Encapsulation Process:

When the ping command is executed from R1 to R2 through the GRE tunnel:

The original ICMP packet will have:

Source IP: 10.1.1.1

Destination IP: 10.3.1.1

This ICMP packet (inner packet) will be encapsulated using GRE.

GRE Encapsulation:

Outer IP Header:

Source IP: 10.0.12.1 (R1 GE0/0/1 interface)

Destination IP: 10.0.12.2 (R2 GE0/0/1 interface)

Inner IP Header:

Source IP: 10.1.1.1 (Tunnel0/0/0 on R1)

Destination IP: 10.3.1.1 (Tunnel0/0/0 on R2)

The outer IP header is used for tunnel routing between the physical interfaces (GE0/0/1).

The inner IP header represents the logical tunnel IPs used for communication between R1 and R2.

3. Correct Answer Analysis:

Option A:

Correct.

The outer IP header addresses are 10.0.12.1 and 10.0.12.2, representing the physical interfaces (GE0/0/1) used to establish the tunnel.

Option C:

Correct.

The inner IP header addresses are 10.1.1.1 and 10.3.1.1, representing the logical tunnel interfaces used for communication.

4. Why Other Options Are Incorrect:

Option B:

Incorrect.

The destination IP in the outer header should be the peer physical IP (10.0.12.2), not the tunnel IP (10.3.1.1).

Option D:

Incorrect.

The inner IP destination is the tunnel IP (10.3.1.1), not the physical IP (10.0.12.2).

The free mobility solution in Huawei iMaster NCE-Campus allows:

Centralized policy management via the controller

Security group-based policies, decoupled from IPs/VLANs

Automatic policy delivery, no need to configure repeatedly per device

Dynamic mapping of users and IPs via security group subscriptions

Exact Extract - Huawei iMaster NCE-Campus Solution White Paper:

“Free mobility uses security groups and centralized control to enable consistent policy enforcement, avoiding repetitive configurations and simplifying policy management.”

Virtual Networks in Huawei CloudCampus Solution:

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

Each VN has its own routing 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 configured using policy-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