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

Understanding MPLS Forwarding Mechanism

MPLS (Multiprotocol Label Switching) is a high-performance forwarding mechanism that operates on two planes:

1️⃣ Control Plane:

Establishes Label Switched Paths (LSPs) using protocols like LDP (Label Distribution Protocol), RSVP-TE (Resource Reservation Protocol - Traffic Engineering), or BGP-LU (BGP Label Unicast).

Assigns labels to packets based on routing policies.

2️⃣ Data Plane (Forwarding Plane):

Uses a Label Forwarding Information Base (LFIB) instead of traditional IP routing.

Packets are forwarded based on labels, not IP addresses.

Analysis of the Answer Choices

✅ C. The system automatically assigns an ID to the upper-layer application that uses a tunnel. This ID is also called the tunnel ID.

Correct: MPLS assigns a Tunnel ID to applications that utilize tunnels (e.g., VPNs, MPLS-TE, or L2/L3 services).

This ID helps differentiate between various tunnel applications, ensuring traffic follows the correct LSP.

❌ A. After an IP packet enters an MPLS domain, the MPLS device forwards the packet based on FIB table queries.

Incorrect: MPLS routers do NOT use the FIB (Forwarding Information Base) for forwarding once labels are assigned.

Instead, they use LFIB (Label Forwarding Information Base) to switch packets based on labels.

❌ B. If the tunnel ID is 0x0, the MPLS forwarding process starts.

Incorrect: If the Tunnel ID is 0x0, MPLS does NOT start; it means no label is assigned, and traditional IP forwarding occurs.

❌ D. If the tunnel ID is not 0x0, the normal IP forwarding process starts.

Incorrect: If the Tunnel ID is not 0x0, MPLS forwards traffic using label switching, not IP forwarding.

✅ Hypertext Transfer Protocol (HTTP) is an application-layer protocol used for:

Accessing web pages and hypermedia content.

Client-server communication over the internet.

Stateless communication with request-response architecture.

Key Features of HTTP:

Application Layer Protocol in the TCP/IP model.

Uses TCP (Port 80) and HTTPS (Port 443) for secure communication.

Supports REST APIs, web applications, and cloud services.

Reference from Huawei HCIE-Datacom Documentation:

Huawei Network Protocol Guide – HTTP and Web Services

HCIE-Datacom Study Material – Application Layer Protocols in TCP/IP Model

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