Huawei H19-402_V1.0 HCSP-Presales – Data Center Network Planning and Design V1.0 Exam Practice Test

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 .

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 .

RDMA (Remote Direct Memory Access) is a key technology in Huawei’s Intelligent Lossless Data Center Network , widely used in high-performance scenarios such as AI training, distributed storage, and HPC.

The statement is correct because RDMA enables direct memory-to-memory data transfer between servers without involving the CPU or operating system in the data path. This bypass mechanism significantly reduces overhead and enables:

Ultra-low latency (microsecond-level communication)

High throughput (efficient use of bandwidth)

Low CPU utilization , freeing compute resources for applications

Although RDMA was originally developed for InfiniBand networks , it is now widely used over Ethernet through technologies like RoCE (RDMA over Converged Ethernet) in Huawei CloudFabric solutions.

To support RDMA effectively, Huawei implements lossless Ethernet mechanisms such as PFC, ECN, and congestion control algorithms to ensure reliable packet delivery.

Therefore, the statement accurately describes RDMA characteristics and 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 routing principles, route selection follows a strict hierarchy. When multiple routing protocols advertise routes to the same destination, the system first compares the route preference (priority) , not the cost. The route with the lowest preference value (highest priority) is selected. Only within the same routing protocol are cost/metric values compared to determine the best route.

Option A is correct because only one optimal route is installed in the routing table at a time, based on protocol preference. Option B is also correct: direct routes are automatically generated for networks connected to local interfaces. Option C is valid as Huawei devices support route import (redistribution) between routing protocols, enabling flexible network design.

Option D is incorrect because it reverses the decision logic. It incorrectly states that cost is compared before priority, which contradicts Huawei’s routing selection process.

Therefore, the false statement is D .

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.

According to Huawei’s CloudFabric intelligent O & M description, the health model is built as a multi-dimensional evaluation system that assesses the network from five dimensions: device, network, protocol, overlay, and service . This means every option listed in the question is part of the CloudFabric health model. Huawei explains that this model integrates telemetry-assisted data such as configuration data, forwarding entry data, logs, and KPI performance information, allowing the platform to detect faults and risks in real time across these five layers.

In practical Huawei CloudFabric operations, the device layer focuses on node health, hardware state, and resource status; the network layer checks connectivity and path quality; the protocol layer verifies control-plane protocols and convergence behavior; the overlay layer evaluates virtualized forwarding networks such as VXLAN fabrics; and the service layer measures the actual service experience and traffic exchange status. Huawei explicitly presents these five as the full health-evaluation scope of CloudFabric intelligent O & M, so the correct response is all five options

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 OpenStack Neutron, the core network abstraction models are Network, Subnet, and Port , which align with Huawei CloudFabric’s logical network design principles. A Network represents a Layer 2 broadcast domain, similar to a VXLAN segment (VNI) in Huawei data center fabrics. It provides tenant-level isolation and forms the foundation for overlay networking.

A Subnet defines the Layer 3 IP addressing scheme within a network, including CIDR blocks, gateway addresses, and DHCP configurations. This aligns with Huawei’s underlay/overlay separation, where IP addressing is critical for both service reachability and automation.

A Port is the connection point between a virtual machine (VM) and the virtual network, equivalent to a virtual NIC. It carries MAC/IP bindings and security policies, similar to endpoint definitions in EVPN-based fabrics.

The option vRouter is incorrect because Neutron uses the concept of a Router , not “vRouter,” and it is considered a higher-layer service component rather than a fundamental network model. Huawei documentation consistently emphasizes these three as the foundational constructs for virtualized network design.

In Huawei CloudFabric VXLAN-based data center networks, active-active access is a key design goal to ensure high availability, load balancing, and optimal resource utilization.

M-LAG (C) is one of the primary technologies used to achieve active-active access at the access layer. It allows a server or downstream device to connect to two leaf switches simultaneously, both of which actively forward traffic. This eliminates single points of failure and ensures link redundancy with load sharing.

EVPN (D) , when used with VXLAN, provides the control plane for MAC/IP route distribution. It enables multi-homing and supports all-active forwarding , ensuring consistent forwarding decisions across the fabric. EVPN also prevents loops and optimizes traffic forwarding using mechanisms like aliasing and mass withdrawal.

Smart Link (A) is typically used for primary/backup (active-standby) scenarios, not active-active. BFD (B) is a fast fault detection protocol and does not provide active-active forwarding capability.

Huawei best practices recommend combining VXLAN + EVPN + M-LAG to achieve highly reliable, scalable, and active-active data center access architectures .

Therefore, the correct answers are C and D .

Huawei data center solutions emphasize the transition toward all-flash data centers as a key enabler of enterprise digital transformation. Traditional HDD-based storage systems cannot meet the performance requirements of modern applications such as AI, big data analytics, cloud computing, and real-time services .

SSD (Solid-State Drive) technology provides significant advantages over HDDs, including:

Ultra-low latency (microseconds vs milliseconds)

High IOPS (Input/Output Operations Per Second)

Better reliability and durability (no mechanical parts)

Lower power consumption and higher density

As a result, SSDs have become the mainstream storage medium in modern data centers, especially in Huawei’s all-flash storage solutions (e.g., OceanStor Dorado) .

All-flash data centers enable:

Faster application response times

Improved user experience

Efficient support for AI and distributed workloads

Simplified storage architecture

Huawei promotes integrating all-flash storage with intelligent lossless networks (RoCE-based) to achieve end-to-end high-performance infrastructure.

Therefore, the statement is TRUE .

In Huawei CloudFabric and modern data center architectures, the underlay and overlay networks are designed as independent layers with clear separation of responsibilities. The underlay network provides basic IP connectivity using standard Layer 3 routing (commonly using protocols such as OSPF, IS-IS, or even static routing), ensuring reliable transport between network devices.

The overlay network, typically implemented using VXLAN with BGP EVPN as the control plane, builds logical Layer 2/Layer 3 services on top of the underlay. Importantly, the overlay does not require the same routing protocol as the underlay. This independence allows flexible design, scalability, and easier evolution of services without modifying the physical infrastructure.

Option A is correct because endpoints (servers, VAS devices) are unaware of the underlay—they only interact with the overlay. Option C is correct as VXLAN is the mainstream overlay encapsulation technology. Option D correctly defines the overlay as a logical abstraction over the physical network.

Thus, statement B is false because Huawei explicitly supports different protocols between underlay and overlay layers.

In Huawei M-LAG design, the peer-link is a critical connection between two M-LAG member devices used for synchronization of control information (such as MAC address tables, ARP entries, and state information) and for forwarding certain types of traffic like broadcast, multicast, and unknown unicast (BUM) traffic when necessary.

However, to prevent traffic loops and duplication , Huawei enforces strict isolation between peer-link interfaces and dual-homed M-LAG member interfaces . Specifically, this relationship is bidirectionally isolated , meaning traffic received from a dual-homed interface is not forwarded to the peer-link and then back to another dual-homed interface, and vice versa.

This bidirectional isolation ensures:

Loop prevention without relying on STP

Avoidance of duplicate packet forwarding

Efficient traffic handling in active-active scenarios

BUM traffic is only forwarded over the peer-link under controlled conditions, not blindly between all interfaces. Huawei CloudFabric best practices emphasize this isolation to maintain stable and predictable forwarding behavior in M-LAG deployments.

Therefore, the correct answer is C (Bidirectionally isolated) .

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 .

Huawei CloudFabric is designed with an open and extensible ecosystem , enabling seamless integration with multiple platforms and services across modern data center environments. This openness is a key principle in Huawei’s architecture, ensuring interoperability and flexibility for diverse workloads.

Third-party VAS interconnection (A) is supported to allow integration with value-added services such as firewalls, load balancers, and security appliances, enabling service chaining and enhanced network functionality.

Container platform interconnection (B) is critical in cloud-native environments. CloudFabric integrates with platforms like Kubernetes, allowing automated network provisioning for containerized applications through APIs and SDN control.

Cloud platform interconnection (C) includes integration with cloud management platforms such as OpenStack and Huawei ManageOne, enabling unified orchestration of compute, storage, and network resources.

Virtualization platform interconnection (D) supports platforms like VMware and FusionSphere, allowing dynamic VM-based networking and automated service deployment.

Huawei documentation emphasizes that CloudFabric supports all these interconnection scenarios to deliver full-stack, multi-platform integration , making all options correct.

In Huawei CloudFabric and VXLAN-based overlay networking, the overlay provides abstraction, flexibility, and scalability by decoupling logical services from the physical infrastructure. NVEs (Network Virtualization Edge nodes) can indeed be deployed on physical switches (such as leaf switches), which is a fundamental capability of hardware-based VXLAN fabrics. Additionally, overlay networks are designed to meet the needs of private cloud environments, offering high performance, simplified O & M, and enhanced security through network segmentation (e.g., VXLAN VNIs).

Overlay networks also support access for both virtual machines and physical servers, ensuring consistent connectivity regardless of workload type.

However, statement D is incorrect. In Huawei’s architecture, especially with BGP EVPN-based VXLAN, the control plane is distributed rather than relying on a controller to synchronously deliver flow tables. Devices dynamically learn and exchange forwarding information using EVPN. Even in SDN-based scenarios with iMaster NCE-Fabric, policy delivery is not strictly synchronous flow table pushing in the traditional sense (like OpenFlow).

Therefore, “controller delivers flow tables synchronously” is not a standard capability of Huawei overlay networks, making option D incorrect.

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.