Free Huawei H19-402_V1.0 Practice Exam with Questions & Answers | Set: 2

In Huawei CloudFabric architecture, logical switches are a key abstraction used to simplify network service deployment and management. These logical switches are built on top of VXLAN Layer 2 networks and represent virtualized broadcast domains (similar to VLANs, but more scalable).

Huawei extends the function of these logical switches by integrating distributed Layer 3 gateway capabilities directly into them. This means that each logical switch can provide both Layer 2 connectivity and Layer 3 routing services (commonly referred to as distributed gateways). These gateways are typically implemented on leaf nodes using VXLAN with BGP EVPN as the control plane.

As a result, traffic between subnets can be routed locally at the ingress leaf switch without needing to traverse to a centralized gateway, significantly improving efficiency and reducing latency. Logical ports connected to these logical switches automatically receive gateway services, enabling seamless inter-subnet communication.

This design aligns with Huawei’s intent of decoupling physical and logical networks while providing scalable, agile, and highly efficient data center networking. Therefore, the statement is TRUE.

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 cloud networking models (aligned with OpenStack and SDN-based architectures), a VPC (Virtual Private Cloud) represents an isolated tenant network environment that contains multiple logical networking components.

Within a VPC:

A logical router provides Layer 3 routing and interconnection between subnets . Typically, one logical router is associated with a VPC to manage north-south and east-west routing.

Multiple logical switches (VXLAN networks or BDs) can be created to represent different Layer 2 segments within the same tenant environment.

Each logical switch can have multiple logical ports , which represent VM interfaces, containers, or service endpoints connected to the network.

This hierarchical design allows:

Flexible network segmentation

Multi-tier application deployment (web/app/db tiers)

Scalable tenant isolation

Huawei CloudFabric, integrated with platforms like iMaster NCE-Fabric and ManageOne , automates the creation and orchestration of these components.

Therefore, the statement is TRUE , as it accurately reflects the standard VPC network model.

In Huawei CloudFabric VXLAN architecture, distributed gateway networking is designed to overcome the limitations of centralized gateway models by pushing Layer 3 gateway functionality down to leaf nodes .

Options B, C, and D are all true advantages of distributed gateways. B highlights deployment flexibility, where a leaf can act as both Layer 2 and Layer 3 VXLAN gateway, enabling efficient east-west traffic forwarding. C and D emphasize improved scalability: each leaf only maintains local ARP/MAC entries , avoiding the bottleneck of a centralized device learning all endpoints. This significantly reduces resource consumption and enhances horizontal scaling.

Option A , however, describes a characteristic of centralized gateway architecture , where inter-subnet traffic is handled by a central node. This approach leads to suboptimal forwarding paths and potential performance bottlenecks, which distributed gateways are specifically designed to eliminate.

Huawei best practices strongly recommend distributed VXLAN gateways for modern data centers due to their scalability, optimal traffic paths, and reduced resource pressure .

Therefore, the correct answer is A .

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 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 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 .

According to Huawei data center network design guidelines, the selection of an underlay routing protocol depends on the scale and complexity of the network. For small to medium-sized data centers , particularly when the number of ToR (Top of Rack) switches is less than 100 , OSPF (Open Shortest Path First) is the recommended routing protocol.

OSPF is a mature and widely deployed link-state protocol that offers fast convergence, simple configuration, and strong interoperability. It is well-suited for smaller-scale spine-leaf networks where operational simplicity is a priority. Huawei recommends OSPF in such scenarios because it provides sufficient scalability and performance without the added complexity of protocols like BGP.

For larger-scale data centers (typically more than 100 ToR switches), Huawei suggests using IS-IS or BGP to improve scalability and simplify large-scale route management. RIP is not suitable due to its limitations in scalability and convergence speed.

Therefore, for networks with fewer than 100 ToR switches, OSPF is the optimal and recommended choice .