Free Practice Questions for Huawei H19-402_V1.0 Exam

In Huawei CloudFabric architecture, the underlay network is the physical IP network that provides basic connectivity and routing reachability for overlay services such as VXLAN.

Option A is correct : the underlay acts as the bearer (transport) network for VXLAN traffic, carrying encapsulated packets between VTEPs.

Option B is correct : the underlay includes both NVE (Network Virtualization Edge) devices that perform VXLAN encapsulation/decapsulation and standard IP forwarding devices (e.g., spine switches).

Option C is correct : the underlay has its own independent control plane , typically using IGP (OSPF/IS-IS) or BGP (EBGP) , and operates independently from the overlay (EVPN).

Option D is false because the underlay network is fundamentally responsible for Layer 3 IP reachability between VTEPs. Without proper L3 routing in the underlay, VXLAN tunnels cannot be established.

Huawei best practices emphasize a simple, stable, and highly reliable underlay , as it is the foundation for all overlay services.

Therefore, the correct answer is D .

In Huawei CloudFabric architecture, a PoD (Point of Delivery) or site is defined as an independent network fault domain under the management of the SDN controller (such as iMaster NCE-Fabric). This design is fundamental for large-scale data center deployments, ensuring clear fault isolation, simplified management, and scalable expansion.

Each PoD typically consists of one or more spine-leaf fabric architectures , which provide high-bandwidth, low-latency, and horizontally scalable connectivity. Within a PoD, all devices operate under a unified control and policy framework delivered by the controller. If a failure occurs within a PoD, it is contained and does not affect other PoDs, thereby improving overall network reliability.

Huawei recommends this modular design approach to support multi-data center deployments, disaster recovery, and service expansion. Multiple PoDs can be interconnected to form a larger cloud fabric, while still maintaining independent fault domains.

Therefore, the statement accurately reflects Huawei CloudFabric design principles and is TRUE.

In Huawei networking, Eth-Trunk (link aggregation) can operate in two modes: manual mode and LACP mode . In manual mode , the Eth-Trunk is statically configured by the administrator, and member interfaces are manually added without using the Link Aggregation Control Protocol (LACP) .

In this mode, all member links that are up are considered active by default , and they simultaneously participate in traffic forwarding and load balancing . Traffic distribution is typically based on hash algorithms (e.g., source/destination MAC or IP), ensuring efficient utilization of available bandwidth.

Unlike LACP mode, manual mode does not perform dynamic negotiation or link state detection between devices. Therefore, it requires consistent configuration on both ends to avoid issues such as loops or traffic blackholing. However, it is simpler and can be useful in controlled environments.

In Huawei data center designs, especially in M-LAG scenarios , LACP is generally preferred for better reliability and fault detection. Still, the statement accurately describes manual mode behavior.

Therefore, the statement is TRUE .

Huawei M-LAG 2.0 is designed to provide ultra-fast convergence and high availability in modern data center networks. One of its key enhancements over traditional M-LAG implementations is the ability to achieve fast fault detection and rapid switchover , minimizing service interruption.

In the event of a single point of failure (such as link or device failure), M-LAG 2.0 leverages mechanisms like BFD (Bidirectional Forwarding Detection) and optimized peer-link synchronization to quickly detect failures and redirect traffic. The switchover time is typically around 5 milliseconds , ensuring near hitless failover for critical services.

This ultra-fast convergence is particularly important for applications such as AI workloads, financial systems, and real-time services , where even small delays can impact performance.

Compared to traditional technologies (which may take tens or hundreds of milliseconds), Huawei M-LAG 2.0 significantly improves network reliability, service continuity, and user experience .

Therefore, the correct answer is C (5 ms) .

In Huawei data center networking, M-LAG (Multi-Chassis Link Aggregation Group) is a critical technology used to provide active-active access, high availability, and link redundancy . It allows a downstream device (such as a server) to establish a single logical Eth-Trunk across two separate physical switches (DeviceA and DeviceB).

From the server’s perspective, both upstream switches appear as one logical device , which eliminates the need for protocols like STP and enables simultaneous forwarding on all active links . This significantly improves bandwidth utilization and avoids blocked links.

The key advantage highlighted in the statement is the improvement of reliability from card-level to device-level . In traditional single-device link aggregation, failures are limited to interface cards. However, with M-LAG, even if an entire switch (device-level failure) goes down, traffic continues to flow through the other active switch without interruption.

Huawei CloudFabric widely adopts M-LAG + VXLAN EVPN to ensure high reliability, fast convergence, and continuous service availability .

Therefore, the statement is TRUE .

Huawei iMaster NCE-Fabric supports both in-band and out-of-band deployment modes, each with distinct characteristics.

In in-band deployment (A, B) :

The management traffic shares the service network , meaning no separate management network is required.

The controller communicates with device management IPs over the service (data) network .

Redundant links can be configured to ensure high reliability and avoid single points of failure.

Therefore, A and B are correct descriptions .

Option C is false because it incorrectly states that the management and service networks are isolated in in-band mode. In reality, they are NOT isolated —they share the same physical infrastructure, which is a defining feature of in-band deployment.

In out-of-band deployment (D) :

A separate management network is used.

iMaster NCE-Fabric connects to devices via dedicated management interfaces through a management switch , ensuring isolation from service traffic.

Huawei recommends choosing deployment mode based on network scale, security, and reliability requirements .

Therefore, the correct answer is C .

In Huawei VXLAN architecture, different gateway types serve distinct roles in tenant communication. The Layer 2 VXLAN gateway is specifically responsible for providing tenant access to the VXLAN network and enabling intra-subnet communication .

A Layer 2 VXLAN gateway (D) connects traditional Layer 2 networks (such as VLAN-based access networks) to the VXLAN overlay. It allows tenant devices or servers to access the VXLAN fabric while maintaining Layer 2 forwarding within the same subnet (same BD/VNI). This means hosts in the same subnet can communicate directly without requiring Layer 3 routing.

In contrast, Layer 3 VXLAN gateways (B) and centralized VXLAN gateways (C) are used for inter-subnet communication , enabling routing between different VXLAN segments. The default VXLAN gateway (A) typically refers to the default gateway IP configured for hosts, which is implemented via Layer 3 gateway functionality.

Huawei CloudFabric design clearly separates Layer 2 access (tenant onboarding and intra-subnet forwarding) from Layer 3 gateway functions (inter-subnet routing) .

Therefore, the correct answer is D (Layer 2 VXLAN gateway) .

In Huawei data center network design, M-LAG (Multi-Chassis Link Aggregation) is widely used to build loop-free Layer 2 topologies without relying on Spanning Tree Protocol (STP) . This is a key advantage in modern CloudFabric architectures.

Traditional Layer 2 networks depend on STP to prevent loops, but STP introduces drawbacks such as blocked links, slow convergence, and inefficient bandwidth utilization . M-LAG eliminates these issues by allowing two physical switches to operate as a single logical device from the perspective of downstream nodes.

With M-LAG:

All links are active-active , maximizing bandwidth usage

Loop prevention is achieved through protocol mechanisms and peer-link synchronization , not STP

Convergence is much faster compared to STP-based designs

Network design becomes simpler and more predictable

Huawei best practices strongly recommend disabling STP in M-LAG-based data center fabrics , especially when combined with VXLAN EVPN, to achieve high performance, fast convergence, and simplified operations .

Therefore, the statement is TRUE .