H12-893_V1-0 Practice Questions

In Huawei’s M-LAG (Multi-Chassis Link Aggregation), the heartbeat link (or peer-link) ensures

communication between member devices. A fault in this link can impact M-LAG operation. Let’s

evaluate each statement:

A. The fault that two master devices exist cannot be detected in the case of a peer-link fault: This is

false. A peer-link fault can be detected, and mechanisms like dual-master detection (e.g., via Inter-

Chassis Communication Link or ICC) can identify if both devices assume master roles, triggering

corrective actions. FALSE.

B. An alarm is triggered: This is true. A peer-link fault generates an alarm to notify administrators, as

it’s a critical failure in M-LAG operation, per Huawei’s fault management system. TRUE.

C. The fault protection mechanism is triggered: This is true. Huawei M-LAG includes protection

mechanisms (e.g., failover to backup links or shutdown of conflicting interfaces) to mitigate peer-link

faults and maintain service continuity. TRUE.

D. Services are affected: This is false. With proper configuration (e.g., redundant links or fast

failover), services should not be affected by a peer-link fault, as M-LAG is designed for high

availability. Impact depends on redundancy, but the design goal is uninterrupted service. FALSE.

Thus, A and D are false statements because dual-master faults can be detected, and services are not

necessarily affected with adequate redundancy.

Reference: Huawei CloudEngine Series Switch Configuration Guide – M-LAG Fault Handling; HCIP-

Data Center Network Training – M-LAG Reliability.

A hypervisor is a software layer that creates and manages virtual machines (VMs) by abstracting

physical resources from the underlying hardware. The question specifies that the hypervisor

virtualizes "memory" and "input/output (I/O) resources," and the task is to provide the missing

resource acronym in uppercase letters. In virtualization contexts, including Huawei’s FusionCompute

or OpenStack with KVM, the primary physical resources virtualized by a hypervisor are:

CPU: The central processing unit (CPU) is virtualized to allocate processing power to VMs, enabling

multi-tenancy and workload isolation.

Memory: Virtualized to provide RAM allocation to VMs, abstracted via memory management units

(MMUs).

I/O Resources: Input/output resources (e.g., NICs, disks) are virtualized to allow VMs to

communicate and store data, often through virtual NICs (vNICs) or virtual disks.

The question lists "memory" and "I/O resources" explicitly, implying the missing resource is CPU, as it

completes the standard triad of virtualized resources in hypervisor design. Thus, the answer is CPU.

Reference: Huawei HCIP-Data Center Network Training – Virtualization Fundamentals;

FusionCompute Architecture Guide.

In Huawei’s CloudFabric Solution, SecoManager (Security Manager) and iMaster NCE-Fabric

(Network Controller) are components of the SDN ecosystem. SecoManager handles security policy

management, while iMaster NCE-Fabric manages network orchestration.

Deployment: These components can be deployed independently but are designed to integrate

seamlessly. Huawei’s architecture supports automated interconnection after installation, leveraging

northbound/southbound APIs or pre-configured integration workflows.

Interconnection: Manual interconnection is not required post-installation; the system automates the

process once both are deployed and configured within the same management domain (e.g., via IP

addressing and authentication).

The statement is FALSE (B) because interconnection is automated, not manual.

Reference: Huawei CloudFabric Data Center Network Solution – Component Integration; HCIP-Data

Center Network Training – SDN Deployment.

Layer 4 load balancing operates at the transport layer (OSI Layer 4), using TCP/UDP protocols to

distribute traffic based on information like IP addresses and port numbers, without inspecting the

application-layer content (Layer 7). Let’s evaluate each option:

A. Nginx: Nginx is a versatile web server and reverse proxy that supports both Layer 4 and Layer 7

load balancing. In its Layer 4 mode (e.g., with the stream module), it balances TCP/UDP traffic,

making it a Layer 4 load balancing technology. This is widely used in Huawei’s CloudFabric DCN

solutions for traffic distribution. TRUE.

B. PPP (Point-to-Point Protocol): PPP is a Layer 2 protocol used for establishing direct connections

between two nodes, typically in WAN scenarios (e.g., dial-up or VPNs). It does not perform load

balancing at Layer 4 or any layer, as it’s a point-to-point encapsulation protocol. FALSE.

C. LVS (Linux Virtual Server): LVS is a high-performance, open-source load balancing solution

integrated into the Linux kernel. It operates at Layer 4, using techniques like NAT, IP tunneling, or

direct routing to distribute TCP/UDP traffic across backend servers. It’s a core Layer 4 technology in

enterprise DCNs. TRUE.

D. HAProxy: HAProxy is a high-availability load balancer that supports both Layer 4 (TCP mode) and

Layer 7 (HTTP mode). In TCP mode, it balances traffic based on Layer 4 attributes, making it a Layer 4

load balancing technology. It’s commonly deployed in Huawei DCN environments. TRUE.

Thus, A (Nginx), C (LVS), and D (HAProxy) are Layer 4 load balancing technologies. PPP is not.

Reference: Huawei CloudFabric Data Center Network Solution – Load Balancing Section; HCIP-Data

Center Network Training – Network Traffic Management.

iMaster NCE-Fabric automates network configuration delivery in Huawei’s CloudFabric. Let’s

evaluate each statement:

A. Logical switches are mainly used for Layer 3 communication between hosts on a VXLAN network.

These switches correspond to Layer 3 gateway configurations such as VBDIF interface and VPN

instance configurations on physical devices: This is false. Logical switches in iMaster NCE-Fabric

primarily handle Layer 2 communication (e.g., bridging within a VNI), corresponding to Bridge

Domains (BDs) and Layer 2 VNIs. Layer 3 communication is managed by gateways, not logical

switches. FALSE.

B. An end port represents an online host. It corresponds to the traffic encapsulation type (whether a

VLAN tag is carried) configured on a Layer 2 sub-interface of a physical device: This is true. End ports

map to host connections, with encapsulation (VLAN-tagged or untagged) configured on sub-

interfaces. TRUE.

C. A logical port is equivalent to an independent physical port that is used by a host to connect to a

VXLAN network. It corresponds to the Layer 2 sub-interface configuration on a physical device: This is

true. Logical ports represent host connections, mapped to Layer 2 sub-interfaces for VXLAN access.

TRUE.

D. Logical switches are mainly used for Layer 2 communication between hosts on a VXLAN network.

These switches correspond to BD and Layer 2 VNI configurations on physical devices: This is true.

Logical switches facilitate Layer 2 connectivity, aligning with BD and VNI settings. TRUE.

Thus, A is the false statement because logical switches are for Layer 2, not Layer 3, communication.

Reference: Huawei CloudFabric Data Center Network Solution – iMaster NCE-Fabric Configuration;

HCIP-Data Center Network Training – Logical Network Mapping.

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.

Reference: Huawei CloudEngine Series Switch Command Reference – VXLAN Commands; HCIP-Data

Center Network Training – Troubleshooting VXLAN.

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.

Reference: Huawei HCIP-Data Center Network Training – BGP EVPN Routes; CloudFabric EVPN

Configuration Guide.

This question pertains to OpenStack, a common virtualization platform in Huawei’s HCIP-Data Center

Network curriculum, where components collaborate to create and manage virtual machines (VMs).

Let’s analyze each component’s role in providing computing, storage, and network resources during

VM creation:

A. Nova: Nova is the compute service in OpenStack, responsible for managing VM lifecycles,

including provisioning CPU and memory resources. It’s essential for providing computing resources

during VM creation. Required.

B. Neutron: Neutron is the networking service, handling virtual network creation, IP allocation, and

connectivity (e.g., VXLAN or VLAN) for VMs. It’s critical for providing network resources during VM

creation. Required.

C. Ceilometer: Ceilometer is the telemetry service, used for monitoring, metering, and collecting

usage data (e.g., CPU utilization, disk I/O) of VMs. While useful for billing or optimization, it does not

directly provide computing, storage, or network resources during VM creation. Not Required.

D. Cinder: Cinder is the block storage service, providing persistent storage volumes for VMs (e.g., for

OS disks or data). It’s essential for providing storage resources during VM creation if a volume is

attached. Required.

Thus, C (Ceilometer) is not required to provision the core resources (computing, storage, network)

for VM creation, as its role is monitoring, not resource allocation.

Reference: Huawei HCIP-Data Center Network Training – OpenStack Architecture; OpenStack Official

Documentation – Service Overview.

Huawei’s CloudFabric intelligent O&M solution, leveraging iMaster NCE-Fabric and FabricInsight,

uses the "1-3-5" principle (detect within 1 minute, locate within 3 minutes, rectify within 5 minutes)

to handle faults. This approach analyzes faults across multiple dimensions. Let’s evaluate each

option:

A . Device: This is supported. The solution monitors device-level metrics (e.g., CPU, memory) to

detect and locate faults. SUPPORTED.

B . Protocol: This is supported. Protocol issues (e.g., OSPF conflicts, BGP errors) are analyzed for fault

detection and resolution. SUPPORTED.

C . Service: This is supported. Service-level faults (e.g., tenant connectivity, VPC issues) are tracked

and addressed. SUPPORTED.

D . Application: This is not supported. The "1-3-5" troubleshooting focuses on network infrastructure

(devices, protocols, services, configurations), not application-layer issues, which are outside its

scope. NOT SUPPORTED.

E . Configuration: This is supported. Configuration errors (e.g., mismatched VNIs) are detected and

rectified as part of the process. SUPPORTED.

Thus, D (Application) is not a dimension supported by the "1-3-5" troubleshooting function.

Reference: Huawei CloudFabric Data Center Network Solution – Intelligent O&M; HCIP-Data Center

Network Training – Troubleshooting Dimensions.

In Linux, the operating system is divided into user space (where applications run) and kernel space

(where the OS core functions execute with privileged access to hardware). Let’s evaluate each

function:

A. The NIC Driver Sends Data Frames: Network Interface Card (NIC) drivers operate in kernel space,

managing hardware interactions like sending and receiving data frames. This is a low-level task

requiring direct hardware access, handled by the kernel’s network stack. Included in Kernel Space.

B. Data Encapsulation: Data encapsulation (e.g., adding headers in the TCP/IP stack) occurs in the

kernel’s network subsystem (e.g., via the protocol stack like IP or TCP). This process prepares packets

for transmission and is a kernel-space function. Included in Kernel Space.

C. Bit Stream Transmission: This refers to the physical transmission of bits over the network,

managed by the NIC hardware and its driver in kernel space. The kernel coordinates with the NIC to

send bit streams, making this a kernel-space function. Included in Kernel Space.

D. Data Encryption: Encryption (e.g., via OpenSSL or application-level VPNs) typically occurs in user

space, where applications or libraries handle cryptographic operations. While the kernel supports

encryption (e.g., IPsec in the network stack), the actual encryption logic is often offloaded to user-

space tools, not a core kernel function in standard contexts. Not Typically in Kernel Space.

Thus, A, B, and C are functions included in the kernel space, aligning with Linux architecture in

Huawei’s DCN context.

Reference: Huawei HCIP-Data Center Network Training – Linux Basics; Linux Kernel Documentation –

Kernel vs. User Space.