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

Understanding User Isolation in the Same VLAN

In a traditional VLAN, all devices within the same VLAN can communicate unless additional security policies are applied. To isolate users within the same VLAN, the following technologies can be used:

✅ B. Port Isolation (Private VLAN or Layer 2 Isolation)

Prevents communication between ports within the same VLAN.

Common in enterprise and campus networks to improve security.

Example: Isolating guest users from employees within the same VLAN.

✅ C. IPSG (IP Source Guard)

Blocks IP address spoofing within the same VLAN.

Uses DHCP snooping binding table to verify whether a device is using an authorized IP address.

✅ D. Ethernet Port Security

Limits the number of MAC addresses allowed per port.

Prevents unauthorized devices from communicating within the VLAN.

❌ A. Super VLAN (Incorrect Choice)

Super VLAN groups multiple VLANs under a single Layer 3 gateway, but it does not provide isolation within the same VLAN.

Real-World Application:

Public Wi-Fi Networks: Ensures that users within the same VLAN cannot communicate with each other.

Enterprise Security: Prevents unauthorized access or attacks within shared VLANs.

✅ Reference: Huawei HCIE-Datacom Guide – VLAN Security and User Isolation Technologies

Comprehensive and Detailed Explanation:

VGMP (Virtual Group Management Protocol) is used in Huawei firewalls for hot standby and high availability.

When is VGMP Activated?✔ When hot standby is enabled, firewalls must synchronize their states to maintain failover capability. ✅✔ VGMP sends packets periodically to check if the standby firewall is operational.

Why Other Options Are Incorrect?❌ Priority increase (B): Does not trigger VGMP packets directly.❌ Link detection timeout (C): Affects failover but does not initiate VGMP packets.❌ Hot standby being disabled (A): Disables VGMP, preventing packets from being sent.

Thus, the correct answer is D.

???? Reference: Huawei HCIE Datacom – Firewall Hot Standby and VGMP

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IPsec (Internet Protocol Security) provides secure communication over IP networks by implementing multiple security functions.

✔ Data Origin Authentication:

Ensures that the sender of the data is genuine and not impersonated.

Uses techniques such as HMAC (Hash-Based Message Authentication Code).

Correct Match: "The receiver verifies the identity of the sender." ✅

✔ Data Encryption:

Protects data confidentiality by encrypting packets using AES, 3DES, or other encryption algorithms.

Ensures that only the intended recipient can decrypt the data.

Correct Match: "The sender encrypts the data, and the receiver decrypts the data." ✅

✔ Data Integrity:

Ensures that data is not altered in transit.

Uses cryptographic hashes (e.g., SHA-256) to verify integrity.

Correct Match: "The receiver verifies received data to determine whether the data has been tampered with." ✅

✔ Anti-Replay:

Protects against packet replay attacks, where an attacker resends captured packets to disrupt communication.

Uses sequence numbers to detect and reject duplicate packets.

Correct Match: "The receiver rejects duplicate data packets." ✅

???? Reference: Huawei HCIE Datacom – IPsec Security Functions

In the Huawei SD-WAN solution, LAN-side devices (such as CPEs and aggregation routers) use various routing protocols to connect to Layer 3 networks and exchange routes dynamically. The supported protocols include:

✅ A. IS-IS (Intermediate System to Intermediate System)

A link-state protocol often used in large enterprise networks for fast convergence and scalability.

✅ B. OSPF (Open Shortest Path First)

A widely used dynamic routing protocol for intra-domain (LAN) connectivity.

Commonly used in enterprise networks to connect SD-WAN edge routers to LAN networks.

✅ C. BGP (Border Gateway Protocol)

BGP is primarily used for WAN and internet connectivity, but it can also be used inside large enterprise networks for LAN-side routing.

BGP enables inter-domain routing and policy-based route control.

✅ D. RIP (Routing Information Protocol)

A legacy distance-vector protocol still supported in some networks for basic LAN routing.

Less preferred due to slow convergence and hop-count limitations.

Reference from Huawei HCIE-Datacom Documentation:

Huawei SD-WAN Deployment Guide – LAN-Side Routing Protocols

HCIE-Datacom Training Material – Routing Configuration in SD-WAN