Huawei Updated H12-891_V1.0 Exam Questions and Answers by sulayman

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 Explanation:❌ 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

Understanding HTTP/1.1 Response Headers

???? What is an HTTP Response?

When a web server responds to an HTTP request, it sends an HTTP response message.

The response contains headers, a status line, and a response body.

Elements of an HTTP Response Header:

✅ A. Status Code → Correct

Indicates the response status (e.g., 200 OK, 404 Not Found).

✅ B. Reason Phrase → Correct

Provides a human-readable explanation of the status code (e.g., OK, Not Found).

✅ C. Protocol Version → Correct

Specifies which HTTP version is being used (e.g., HTTP/1.1).

❌ D. Response Method → Incorrect

The HTTP method (GET, POST, etc.) is part of the request, not the response.

SSH Public Key Authentication

In public key authentication mode, the SSH client must generate a key pair (public and private keys) before connecting to an SSH server.

✅ C. ssh-keygen -t dsa (Correct Answer)

DSA (Digital Signature Algorithm) key generation for SSH authentication.

Generates a private key (id_dsa) and a public key (id_dsa.pub).

Congestion Avoidance in Networking

Congestion avoidance mechanisms prevent packet loss and delay by managing queues before congestion occurs.

Common Congestion Avoidance Techniques:

Weighted Random Early Detection (WRED) – Randomly drops low-priority packets before congestion builds up.

Explicit Congestion Notification (ECN) – Marks packets instead of dropping them to signal congestion.

Queue Management – Techniques like priority queuing (PQ) and weighted fair queuing (WFQ) help prevent congestion.

Reference from Huawei HCIE-Datacom Documentation:

Huawei QoS Configuration Guide – Congestion Avoidance Technologies

HCIE-Datacom Study Material – Traffic Management and Queue Optimization