H12-891_V1.0 Exam Dumps : HCIE-Datacom V1.0

The MPLS header consists of:

Label (20 bits) – Label value used for forwarding.

EXP (3 bits) – QoS field (Class of Service).

S bit (1 bit) – Bottom-of-Stack indicator.

TTL (8 bits) – Time-to-Live, similar to the TTL field in the IP header.

Function of TTL in MPLS:

It is used to prevent infinite loops.

Every LSR decrements the TTL by 1.

When TTL reaches 0, the packet is discarded.

This mirrors the behavior of IP TTL and ensures loop prevention in MPLS networks.

Correct answer: D. This field is used to prevent packet forwarding loops, similar to the TTL field in an IP header.

When selecting core devices for a WAN in enterprise networks, considerations typically include:

Service volume: Ensures the core device can handle expected traffic.

Physical location: Important for latency, redundancy, and network design.

Node quantity: Affects topology, scalability, and routing complexity.

Device naming conventions, however, are purely administrative and do not affect the functional selection of core devices.

Correct answer: A. Device naming conventions

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