H19-402_V1.0 Huawei HCSP-Presales – Data Center Network Planning and Design V1.0 Free Practice Exam Questions (2026 Updated)

The statement is false due to an incorrect description of in-band management communication .

Huawei iMaster NCE-Fabric indeed supports both in-band and out-of-band deployment modes , but the interfaces used are misrepresented:

In in-band mode , iMaster NCE-Fabric uses southbound interfaces (not northbound) to communicate with switches over the service network . These southbound interfaces are responsible for delivering configurations and collecting device information.

In out-of-band mode , the description is correct: the controller connects to device management interfaces via a dedicated management network , ensuring separation from service traffic.

The confusion arises because:

Northbound interfaces are used for communication between the controller and upper-layer systems (e.g., cloud platforms like OpenStack or ManageOne).

Southbound interfaces are used for communication between the controller and network devices .

Huawei architecture strictly separates these roles to enable clear control-plane layering and automation .

Therefore, because the statement incorrectly mentions northbound interfaces in in-band mode , the correct answer is FALSE .

In Huawei data center and network security architecture, native encryption support is a key differentiator between tunneling technologies and secure communication protocols.

SSL VPN (C) and IPsec VPN (D) both provide built-in encryption mechanisms . SSL VPN uses TLS/SSL protocols to encrypt application-layer traffic, making it suitable for secure remote access. IPsec VPN operates at the network layer and provides confidentiality, integrity, and authentication through protocols such as ESP (Encapsulating Security Payload), making it widely used for site-to-site and data center interconnection security.

On the other hand, VXLAN (A) and GRE (B) are encapsulation/tunneling technologies that do not inherently provide encryption. VXLAN is used for overlay networking (e.g., tenant isolation in CloudFabric), while GRE is used for simple tunneling across IP networks. Both require additional security mechanisms (such as IPsec) if encryption is needed.

Huawei CloudFabric design guidelines clearly separate overlay encapsulation (VXLAN) from security protocols (IPsec/SSL) , emphasizing that encryption must be implemented using dedicated security technologies.

Therefore, the correct answers are C and D .

In Huawei data center networking, especially within Intelligent Lossless Data Center Network design, incast traffic is a well-known challenge in distributed systems such as AI computing clusters and distributed storage architectures .

In an incast scenario , a large number of servers simultaneously send traffic to a single destination (e.g., parameter server in AI training or storage node in distributed storage). This sudden aggregation of traffic can quickly overflow switch buffers , leading to packet loss, increased latency, and throughput degradation .

Huawei identifies incast as a primary cause of network congestion in modern data centers. To mitigate this, CloudFabric solutions implement advanced congestion control technologies such as:

PFC (Priority Flow Control) to prevent packet loss

ECN (Explicit Congestion Notification) for early congestion signaling

AI-driven traffic scheduling and load balancing

These mechanisms help build a lossless Ethernet fabric , which is essential for RDMA-based AI workloads and high-performance storage systems.

Therefore, the statement is TRUE , as incast traffic is indeed prone to causing congestion in such environments.

In Huawei CloudFabric architecture, service integration and flexible deployment of security devices such as firewalls are key design principles. Firewalls can be deployed in multiple ways depending on service requirements, traffic patterns, and scalability considerations.

Firewalls can be connected to:

Service leaf nodes : These are dedicated nodes used for service insertion (e.g., firewall, load balancer). Traffic can be steered through these nodes using policy-based routing or service chaining.

Border leaf nodes (combined with service leaf role) : In some designs, border leaf nodes (which connect to external networks such as WAN or Internet) can also integrate service functions, including firewall connectivity. This reduces hardware requirements and simplifies deployment.

Huawei supports both centralized and distributed service deployment models , allowing firewalls to be flexibly inserted into the network fabric. Integration is typically achieved using VXLAN, EVPN, and service chaining technologies , ensuring seamless traffic steering and policy enforcement.

This flexibility enhances:

Network scalability

Security enforcement

Operational simplicity

Therefore, the statement is TRUE .

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, particularly in large-scale CloudFabric architectures, Points of Delivery (PoDs) are a fundamental concept used to enable modular scalability, simplified management, and efficient resource pooling. A PoD typically consists of a group of servers, access switches (Leaf), and sometimes aggregation resources that function as a repeatable building block within the data center.

By dividing a data center into multiple PoDs, operators can achieve horizontal scalability , where additional capacity is added by deploying new PoDs without impacting existing services. This aligns with Huawei’s spine-leaf architecture, where each PoD connects to a common spine layer, ensuring consistent performance and low latency.

PoDs also improve fault isolation and operational efficiency , as issues can be contained within a specific module. From a management perspective, this structure simplifies provisioning, monitoring, and automation through platforms like iMaster NCE-Fabric.

Therefore, the statement is TRUE , as PoD-based design is a widely adopted best practice in Huawei data center planning and modern cloud infrastructures.

In Huawei Cloud Stack (HCS) architecture, ManageOne serves as the unified cloud management platform , responsible for end-to-end orchestration, service provisioning, and lifecycle management across compute, storage, and network resources. It provides a centralized portal for administrators and tenants, enabling automated deployment and O & M of cloud services.

FusionSphere is Huawei’s virtualization platform (similar to OpenStack + hypervisor integration) and operates at the resource layer, not as the top-level management system. Hypervisor and Virtual Machine Monitor (VMM) are components of the virtualization layer that manage virtual machines on physical servers, but they lack cloud-wide orchestration capabilities.

From a Huawei CloudFabric perspective, ManageOne integrates with controllers like iMaster NCE-Fabric to automate network provisioning, enabling seamless underlay and overlay configuration. It supports multi-data-center management, self-service portals, and policy-driven automation, which are essential for modern cloud data center operations.

Therefore, ManageOne is the correct answer as the cloud management platform in HCS.

In Huawei CloudFabric VXLAN design, distributed gateway architecture is a key enhancement over traditional centralized gateway models, especially for large-scale data centers.

Option A is correct because distributed gateways (typically deployed on leaf nodes) only maintain local ARP/MAC entries for directly connected hosts. This significantly reduces ARP table pressure compared to centralized gateways, where a single device must learn all entries. This improves scalability and performance , which is critical in multi-tenant environments.

Option C is also correct as Huawei leaf switches can simultaneously act as Layer 2 VXLAN gateways (bridging) and Layer 3 VXLAN gateways (routing) . This enables distributed inter-subnet routing directly at the access layer, reducing latency and improving east-west traffic efficiency.

Option B is incorrect because it describes a limitation of centralized gateways , where traffic must traverse a central node, leading to suboptimal paths. Distributed gateways eliminate this issue.

Option D is also incorrect as it again describes centralized gateway constraints, not distributed ones.

Thus, distributed VXLAN gateways provide better scalability, optimal forwarding paths, and flexible deployment , making A and C correct .

In Huawei data center network design, VXLAN overlay deployment models are categorized based on where VTEPs (VXLAN Tunnel End Points) are located. These include host-based overlay, network-based overlay, and hybrid overlay.

In a host overlay , VTEPs are implemented only on vSwitches (such as those within hypervisors), and physical switches only provide IP transport (underlay). In a network overlay , VTEPs are deployed only on physical switches (typically leaf switches), and servers are unaware of VXLAN encapsulation.

The hybrid overlay model combines both approaches. In this design, VTEPs can exist on both vSwitches (inside virtualized hosts) and physical switches (such as leaf devices). This allows greater flexibility, supporting mixed environments where some workloads use hypervisor-based encapsulation while others rely on hardware VTEPs for higher performance or integration with bare-metal servers.

Huawei CloudFabric supports hybrid overlay to enable smooth evolution from traditional to fully virtualized environments. Therefore, the correct answer is Hybrid overlay (C) .

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 .

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 .

Comprehensive and Detailed 150 to 200 words of Explanation From Huawei data center:

After rechecking against Huawei’s own materials, the verified multi-select answer is B and D . Huawei documentation for Elastic Load Balance, which is the load-balancing architecture referenced in Huawei cloud/data center designs, states that for Layer 4 traffic using TCP/UDP , incoming traffic is routed only through the LVS cluster . For Layer 7 traffic using HTTP/HTTPS , incoming traffic is routed first to the LVS cluster and then to the Nginx cluster before reaching backend servers. That means Huawei explicitly uses LVS for L4 load balancing and Nginx together with LVS for L7 load balancing.

By contrast, IP ECMP is a Layer 3 equal-cost forwarding/load-sharing mechanism, not an L4-L7 service load balancer in Huawei’s CloudFabric context. Huawei’s ECMP documentation discusses route-based traffic distribution in the IP layer, which is fundamentally different from application/service load balancing.

In Huawei CloudFabric design, M-LAG (Multi-Chassis Link Aggregation) is widely used to provide active-active forwarding and high availability at the access and border layers. When border leaf nodes are deployed in an M-LAG pair, they typically connect to upstream PE (Provider Edge) devices in a dual-homing (square topology) manner, ensuring both link-level and device-level redundancy.

However, Huawei design guidelines clearly state that an interconnection link (commonly called a peer-link or bypass link) between M-LAG devices is mandatory. This link is essential for synchronization of forwarding states, MAC address tables, ARP/ND entries, and control plane information between the two devices. It also ensures proper traffic forwarding in failure scenarios, such as when one device loses its uplinks but remains operational.

Without this peer-link, traffic consistency and loop prevention mechanisms cannot function correctly, leading to potential traffic loss or loops. Therefore, even in dual-egress scenarios with PE devices, the bypass/peer link is still required.

Hence, the statement is FALSE.

In Huawei CloudFabric architecture, server leaf nodes and service leaf nodes have distinct roles, even though both can function as NVEs (Network Virtualization Edge devices) in a VXLAN network.

A server leaf node primarily provides access for compute resources , such as physical servers and virtual machines. It acts as a common NVE, handling VXLAN encapsulation/decapsulation for tenant traffic and enabling communication within the overlay network.

However, firewalls and load balancers (LBs) are classified as value-added service (VAS) devices and are typically connected to service leaf nodes , not standard server leaf nodes. Service leaf nodes are specifically designed to handle service insertion, traffic steering, and policy-based forwarding required for these devices.

Although in some simplified deployments roles may be combined, Huawei standard design clearly separates:

Server leaf → compute access

Service leaf → VAS device access (FW, LB, etc.)

Therefore, the statement is FALSE , as server leaf nodes do not typically provide access for firewalls and load balancers in standard CloudFabric architecture.

In Huawei M-LAG design, strict requirements ensure stability and consistency between the two participating devices. Option A is false because M-LAG must be established between devices of the same type and model (or at least fully compatible models) . This ensures consistent forwarding behavior, synchronization of MAC/ARP tables, and proper operation of the peer-link and keepalive mechanisms. Using different device types is not supported and may lead to instability.

Option B is correct : unidirectional isolation is relevant only for dual-homed scenarios. If a device is single-homed, this mechanism is not applied.

Option C is correct : the peer-link is a critical connection between M-LAG peers and is typically configured as an Eth-Trunk (link aggregation) to ensure high bandwidth and redundancy.

Option D is also correct : peer-link interfaces are dedicated and cannot be used for other services, ensuring reliable synchronization and control-plane communication.

Huawei best practices emphasize homogeneous device deployment for M-LAG to guarantee predictable and stable operation.

Huawei data center design guidelines emphasize end-to-end reliability across all layers of the physical network, including uplinks, devices, interconnections, and server access. All the listed options reflect valid reliability principles.

Option A is correct because ECMP (Equal-Cost Multi-Path) is a fundamental mechanism in spine-leaf architectures, ensuring load balancing and fast convergence when links fail. Option B highlights modular switch reliability , where inter-card connections prevent single-card failures from impacting connectivity.

Option C describes the DAD (Dual-Active Detection) mechanism in M-LAG scenarios. When a peer-link failure occurs, DAD ensures that only one device remains active, preventing split-brain conditions and maintaining network stability.

Option D addresses server-side reliability , where dual-homing with NIC teaming (active-active or active-standby) ensures uninterrupted service in case of link or device failure.

Together, these principles form Huawei’s comprehensive approach to building highly reliable and resilient data center networks.

In Huawei CloudFabric and VXLAN-based data center designs, it is a best practice to use the IP address of a loopback interface as the VTEP (VXLAN Tunnel End Point) source address instead of a physical interface IP. This recommendation is based on reliability, stability, and operational flexibility.

A loopback interface is always in the UP state as long as the device is operational, whereas physical interfaces may go down due to link failures. If a physical interface IP is used as the VTEP source, any link failure would cause VXLAN tunnels to flap, impacting service continuity. In contrast, loopback interfaces remain reachable through the underlay network via dynamic routing protocols such as OSPF, IS-IS, or BGP, ensuring consistent tunnel endpoints.

Additionally, using loopback addresses supports ECMP (Equal-Cost Multi-Path) forwarding in the underlay, improving load balancing and network utilization. Huawei documentation strongly emphasizes this design principle to enhance VXLAN tunnel resilience and simplify network operations. Therefore, the statement is TRUE.