Huawei Updated H19-402_V1.0 Exam Questions and Answers by luka

In Huawei VXLAN architecture, all listed statements accurately reflect core design concepts used in CloudFabric deployments.

A is correct: a Virtual Interface (VBDIF/VirtualIF) is a Layer 3 interface associated with a Bridge Domain (BD) , enabling inter-subnet routing (distributed gateway function).

B is correct: Huawei VXLAN commonly uses a 1:1 mapping between VNI and BD , where the BD acts as the Layer 2 forwarding domain. This mapping ensures clear separation of tenant networks and simplifies forwarding logic.

C is correct: VXLAN encapsulation uses VTEP (VXLAN Tunnel Endpoint) IP addresses . The source IP is the local VTEP, and the destination IP is the remote VTEP. Together, they logically represent the VXLAN tunnel used for transporting overlay traffic across the IP underlay.

D is also correct: a VAP (Virtual Access Point) represents the service access interface. On Huawei CE switches, VAPs are typically implemented using VLAN-based access , meaning VLANs act as the entry point for VXLAN services.

These concepts are fundamental in Huawei EVPN-VXLAN fabrics, enabling scalable, multi-tenant, and automated data center networking.

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 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 .