Huawei H12-893_V1.0 Practice Test - Questions Answers, Page 3

VXLAN is an overlay technology that encapsulates Layer 2 frames within UDP packets to create scalable virtual networks, widely used in Huawei's data center architectures. Let's evaluate each statement:

A . A VXLAN tunnel endpoint that performs encapsulation is called a VNI: This is incorrect. A VXLAN Tunnel Endpoint (VTEP) is the device (physical or virtual) that performs encapsulation and decapsulation. The VNI (VXLAN Network Identifier) is a 24-bit field in the VXLAN header that identifies the virtual network, not the endpoint. FALSE.

B . VXLAN uses ECMP of the underlay network to improve network forwarding performance: Equal-Cost Multi-Path (ECMP) routing in the underlay network allows VXLAN to distribute traffic across multiple paths, enhancing load balancing and performance. This is a standard feature in Huawei's VXLAN implementations. TRUE.

C . A VXLAN network is built based on UDP: VXLAN encapsulates Ethernet frames within UDP packets (using port 4789), making it a UDP-based overlay protocol. This is a core characteristic of VXLAN. TRUE.

D . VXLAN expands the number of subnets to 16 million and supports multi-tenancy: With a 24-bit VNI, VXLAN supports up to 16 million (2^24) unique network identifiers, enabling extensive subnet segmentation and multi-tenancy, a key advantage over traditional VLANs (4096 limit). TRUE.

Thus, A is the false statement because a VTEP, not a VNI, is the tunnel endpoint that performs encapsulation.

BGP EVPN (Ethernet VPN) extends BGP to provide control plane functionality for VXLAN overlays, including in Huawei's data center networks. EVPN defines several route types to advertise different types of information:

Type 1: Auto-discovery routes for EVPN instances.

Type 2: MAC/IP Advertisement routes for host reachability.

Type 3: Inclusive Multicast Ethernet Tag routes for multicast traffic.

Type 4: Ethernet Segment routes for multi-homing.

Type 5: IP Prefix routes for advertising host IP routes and external network routes, enabling inter-subnet and external connectivity.

The question specifies routes used to advertise 'host IP routes and external network routes,' which aligns with Type 5 routes. These routes carry IP prefix information and a Layer 3 VNI, facilitating Layer 3 routing within the EVPN domain or to external networks. Thus, the answer is 5.

VXLAN (Virtual Extensible LAN) tunnels are used to encapsulate Layer 2 traffic over a Layer 3 network, a key component in Huawei's CloudFabric data center solutions. Let's evaluate each statement:

A . A VXLAN tunnel is identified by a pair of VTEPs: This is true. A VXLAN tunnel is identified by the pair of VXLAN Tunnel Endpoint (VTEP) IP addresses (local and remote), along with the VNI (VXLAN Network Identifier). This ensures unique tunnel identification. TRUE.

B . After a tunnel is established, if one end of the tunnel goes Down, the other end may not go Down: This is true. VXLAN tunnels are unidirectional, and the status of one end does not automatically affect the other unless the underlay network connectivity (e.g., Layer 3 reachability) is lost. The remote VTEP may remain operational if it can still encapsulate/decapsulate traffic. TRUE.

C . For a static tunnel, you need to manually configure the local and remote VNIs: This is true. In a static VXLAN tunnel, administrators must manually configure the VNI and VTEP IP addresses on both ends, as there is no dynamic control plane (e.g., BGP EVPN) to automate the process. TRUE.

D . Dynamic tunnels depend on EVPN Type 5 routes to transmit information: This is false. Dynamic VXLAN tunnels rely on BGP EVPN as the control plane, but Type 5 routes (IP Prefix routes) are specifically used for advertising host IP routes and external network routes, not for general tunnel establishment. Dynamic tunnel setup primarily uses Type 2 (MAC/IP Advertisement) and Type 3 (Multicast) routes to exchange VNI and VTEP information. Type 5 routes are relevant for Layer 3 routing, not the initial tunnel setup. FALSE.

Thus, D is the false statement because dynamic tunnels depend on EVPN Type 2 and Type 3 routes, not Type 5, for initial establishment.

On Huawei CloudEngine (CE) series switches, VXLAN tunnel monitoring and troubleshooting involve specific commands to diagnose issues such as tunnel Down status or failed dynamic establishment. Let's evaluate each option:

A . Run the display vxlan statistics command to check the cause of the fault: This command provides statistics on VXLAN tunnel traffic, including packet drops, encapsulation/decapsulation counts, and errors. It helps identify issues like misconfiguration or network congestion, making it a valid troubleshooting tool. TRUE.

B . Run the display vxlan peer command to check the cause of the fault on the peer device of the tunnel: This command displays information about VXLAN peers, including their IP addresses, VNIs, and reachability status. Checking the peer device's status can reveal connectivity or configuration mismatches, aiding fault diagnosis. TRUE.

C . Run the display vxlan troubleshooting command to check the causes of at most the latest five failures to dynamically establish a VXLAN tunnel: This command logs and displays troubleshooting details, including the latest five failure reasons for dynamic tunnel setup (e.g., BGP EVPN issues or reachability problems). This is a standard feature on Huawei CE switches. TRUE.

D . Run the display vxlan troubleshooting command to check at most the latest five reasons why a VXLAN tunnel goes Down: This command also tracks reasons for tunnel Down events (e.g., underlay failure, peer unreachability), limited to the latest five incidents. This is consistent with Huawei's troubleshooting capabilities. TRUE.

All options A, B, C, and D are true, as they represent valid commands and approaches to troubleshoot VXLAN tunnel issues on Huawei CE switches.

V-STP (Virtual Spanning Tree Protocol) is a Huawei-specific enhancement of the Spanning Tree Protocol (STP) designed to prevent Layer 2 loops in complex network topologies, including Multi-Chassis Link Aggregation (M-LAG) deployments on Huawei CloudEngine (CE) series switches.

M-LAG Overview: M-LAG allows two switches to appear as a single logical device, connecting to downstream devices via Link Aggregation Groups (LAGs). Without proper loop prevention, incorrect configurations (e.g., misconfigured ports) or physical connections (e.g., redundant links) can cause broadcast storms.

V-STP Role: V-STP extends STP to handle virtualized environments and M-LAG scenarios. It ensures that only one path is active in a loop-prone topology by blocking redundant links, preventing loops caused by misconfigurations or unintended connections. In M-LAG, V-STP coordinates with the peer-link to maintain a loop-free topology.

The statement is TRUE (A) because V-STP is designed to prevent loops in M-LAG deployments due to incorrect configurations or connections.

M-LAG (Multi-Chassis Link Aggregation) on Huawei CE series switches enhances high availability and load balancing by making two switches appear as one. Let's evaluate each statement:

A . Multi-level M-LAG is mainly used to construct a large Layer 2 network in a DCN or directly connect DCNs at Layer 2: This is true. Multi-level M-LAG extends the topology across multiple layers or data centers, facilitating large Layer 2 domains, a common use case in Huawei DCNs. TRUE.

B . In multi-level M-LAG networking, you can manually configure the root bridge to prevent STP loops: This is true. Manual configuration of the root bridge (e.g., using STP priority) is supported to optimize path selection and prevent loops, especially in complex M-LAG setups. TRUE.

C . Multi-level M-LAG must be configured based on V-STP: This is false. While V-STP can be used to prevent loops, M-LAG does not require V-STP specifically. Standard STP, RSTP, or MSTP can also be configured, depending on the network design. The requirement is loop prevention, not a mandatory V-STP dependency. FALSE.

D . M-LAG networking can be classified into single-level M-LAG networking and multi-level M-LAG networking: This is true. Single-level M-LAG connects two switches directly to devices, while multi-level M-LAG extends across additional layers or devices, a recognized classification in Huawei documentation. TRUE.

Thus, C is the false statement because multi-level M-LAG does not mandate V-STP configuration.

In Huawei's M-LAG (Multi-Chassis Link Aggregation) on CE series switches, the two member devices synchronize critical information over the peer-link to ensure seamless operation and failover. Let's evaluate each option:

A . ACL information: Access Control List (ACL) configurations are typically not synchronized in M-LAG, as they are device-specific security policies. Synchronization of ACLs is not a standard feature in Huawei's M-LAG implementation. NOT SYNCHRONIZED.

B . STP status: Spanning Tree Protocol (STP) status (e.g., port roles, states) is synchronized to maintain a consistent loop-free topology across M-LAG peers, especially when V-STP or other STP variants are used. SYNCHRONIZED.

C . Device name: Device names are administrative identifiers and are not synchronized, as they do not impact traffic forwarding or M-LAG functionality. NOT SYNCHRONIZED.

D . LACP information: Link Aggregation Control Protocol (LACP) status (e.g., link states, aggregation details) is synchronized to ensure both M-LAG devices present a unified LAG to downstream devices, supporting load balancing and failover. SYNCHRONIZED.

Thus, B (STP status) and D (LACP information) are synchronized between M-LAG devices.

Microsegmentation in Huawei's data center networks (e.g., CloudFabric with SDN) divides Endpoint Groups (EPGs) to enforce fine-grained security policies. EPGs group endpoints (e.g., VMs) based on attributes. Let's evaluate each option:

A . Operating system: This is true. The OS type (e.g., Linux, Windows) can be used to segment EPGs, enabling policy enforcement based on OS-specific security needs. TRUE.

B . VM name: This is true. VM names can be used as identifiers for microsegmentation, allowing policies to target specific VMs. TRUE.

C . IP address: This is true. IP addresses are commonly used to define EPG boundaries, especially for network-based segmentation. TRUE.

D . MAC address: This is true. MAC addresses can segment EPGs, particularly for Layer 2-based policies or device-specific isolation. TRUE.

All options A, B, C, and D are valid conditions for microsegmentation to divide EPGs in Huawei's implementation.

Huawei's CloudFabric solution provides an SDN-based framework for data center network management, supporting automation across the network lifecycle. Let's evaluate each phase:

A . Planning and construction: This is true. CloudFabric automates network design, resource allocation, and deployment during the planning and construction phase using tools like iMaster NCE. TRUE.

B . Service provisioning: This is true. Automated service orchestration (e.g., VXLAN tunnel setup, tenant configuration) is a key feature during provisioning. TRUE.

C . O&M and monitoring: This is true. CloudFabric offers real-time monitoring, fault detection, and performance optimization through centralized management. TRUE.

D . Change optimization: This is true. The solution supports automated upgrades, policy adjustments, and optimization based on analytics, covering the change management phase. TRUE.

All phases A, B, C, and D are supported by CloudFabric's full-lifecycle automation.