H12-893_V1.0 Exam Questions & Answers

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.

In Huawei's CloudFabric Solution, the iMaster NCE-Fabric controller manages the network in computing scenarios (e.g., virtualized environments). Controller interconnection with external systems can be mandatory or optional depending on functionality. Let's evaluate each option:

A . Interconnection with FabricInsight: This is optional. FabricInsight is an analytics and assurance tool that enhances visibility and troubleshooting but is not required for basic controller operations in the computing scenario. OPTIONAL.

B . Interconnection with the authentication server: This is mandatory. Authentication servers (e.g., RADIUS, TACACS+) are essential for securing access to the controller and managed devices, a core requirement in computing scenarios. NOT OPTIONAL.

C . Interconnection with eSight: This is optional. eSight is a network management platform that provides additional monitoring and management capabilities, but it is not necessary for core controller functionality. OPTIONAL.

D . Interconnection with the VMM (Virtual Machine Manager): This is mandatory. Interconnection with a VMM (e.g., FusionCompute, OpenStack) is required to manage virtualized computing resources and orchestrate network services in the computing scenario. NOT OPTIONAL.

Thus, A (Interconnection with FabricInsight) and C (Interconnection with eSight) are optional services for controller interconnection.

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.

In Huawei's CloudFabric Solution, iMaster NCE-Fabric automates overlay network (e.g., VXLAN) configuration, while the underlay network is manually deployed. Tenant hosts failing to access external networks indicate a connectivity issue, likely at the overlay-underlay boundary or security layer. Let's evaluate each option as a possible cause:

A . No return route is configured on the PE: This is a possible cause. The Provider Edge (PE) device (e.g., border leaf or router) must have a return route to the tenant's VXLAN network for external access. Without it, traffic from external networks cannot reach the DC. POSSIBLE CAUSE.

B . The engineer did not check whether the service loopback interface needs to be configured on the VXLAN network based on the switch model: This is a possible cause. Some Huawei switch models (e.g., CE series) require a service loopback interface as the VTEP source IP. If omitted or misconfigured based on the model, external connectivity fails. POSSIBLE CAUSE.

C . No firewall security policy is configured when host traffic passes through the firewall: This is a possible cause. If a firewall is in the path (e.g., between tenant VPC and external network), a missing security policy (e.g., allowing outbound traffic) blocks access. POSSIBLE CAUSE.

D . The MAC address of the NVE interface on the VXLAN network is not manually specified: This is not a possible cause. The Network Virtualization Edge (NVE) interface in VXLAN does not require a manually specified MAC address; it uses the switch's system MAC or auto-generates one. iMaster NCE-Fabric typically handles this automatically, and manual specification is neither required nor a common fault point for external access issues. NOT A POSSIBLE CAUSE.

Thus, D is not a possible cause of the fault.

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.