H12-893_V1.0 HCIP-Data Center Network V1.0 Questions and Answers

OSPF (Open Shortest Path First) is a routing protocol used in the underlay network of Huawei’s CloudFabric DCNs. Let’s evaluate each statement:

A. Typically, the IP address of Loopback0 is configured as the VTEP IP address and the same IP address is planned for active-active leaf nodes in the same group:This is true. Loopback0 IP is commonly used as the VTEP IP for stability, and in active-active leaf node groups (e.g., M-LAG), the same IP can be configured with VRRP or anycast to ensure consistency.TRUE.

B. The network type of spine and leaf nodes can be set to P2P in order to accelerate convergence:This is true. Setting OSPF network type to Point-to-Point (P2P) on spine-leaf links reduces overhead (e.g., no DR/BDR election) and speeds up convergence, a recommended practice in Huawei DCNs.TRUE.

C. This routing design is recommended when the DC has more than 300 switches:This is false. OSPF is suitable for smaller to medium-sized DCNs (e.g., up to 200-300 switches). For larger networks (>300 switches), EBGP is preferred due to better scalability and reduced complexity.FALSE.

D. It is recommended that all devices be planned in Area 0:This is false. While a single Area 0 is possible for small DCNs, multi-area OSPF is recommended for larger networks to manage scalability and reduce routing table size, avoiding a flat Area 0 design.FALSE.

Thus,A and Bare true statements about OSPF routing design in a DC underlay.References:Huawei CloudFabric Data Center Network Solution – Underlay Design; HCIP-Data Center Network Training – OSPF in DCN.

Traditional data center networks (DCNs) often suffer from single points of failure, limited scalability, and traffic bottlenecks. Both M-LAG and stacking address these issues, but their suitability for 24/7 service continuity differs.

M-LAG Benefits:M-LAG (Multi-Chassis Link Aggregation) on Huawei CE switches allows two devices to act as a single logical switch, providing active-active forwarding, high availability, and rapid failover (e.g., via peer-link synchronization). It supports non-stop service during device failures, making it ideal for 24/7 continuity.

Stacking Benefits:Stacking combines multiple switches into a single logical unit, sharing a control plane. While it improves scalability and simplifies management, a stack master failure can disrupt the entire stack unless redundancy is perfectly configured, potentially affecting service continuity.

Comparison:M-LAG’s decentralized design and real-time synchronization offer better fault isolation and recovery compared to stacking, where a master switch failure impacts the stack. Huawei documentation highlights M-LAG’s superiority for high-availability scenarios like 24/7 operations.

The statement isTRUE (A)because M-LAG is indeed a better choice than stacking for ensuring 24/7 service continuity due to its robust failover and redundancy features.References:Huawei CloudEngine Series Switch Configuration Guide – M-LAG vs. Stacking; HCIP-Data Center Network Training – High Availability Solutions.

To identify the false statement, we evaluate each option based on standard M-LAG documentation, such as Huawei’s and Arista’s guidelines, which are commonly referenced in HCIP-Data Center Network training.

Option A: In loose mode, if Type 1 configurations of the two M-LAG member devices are inconsistent, the member interface on the M-LAG backup device is in Error-Down state and an alarm is generated, indicating that Type 1 configurations on the two devices are inconsistent.

Evaluation: This statement is true. In loose mode, inconsistencies in Type 1 (key) configurations are still critical, as they can affect M-LAG operation. According toHuawei M-LAG Configuration Guide, when Type 1 configurations are inconsistent in loose mode, the system may place the member interface on the backup device into an Error-Down state and generate an alarm to alert administrators. This ensures that critical issues are flagged, even in loose mode, to prevent loops or packet loss.

Conclusion: True.

Option B: If Type 1 configurations of the two M-LAG member devices are inconsistent, certain problems may occur, such as loops and long-period packet loss when the status is normal.

Evaluation: This statement is true. Type 1 configurations are essential for M-LAG operation, and inconsistencies can lead to severe network issues. For example, mismatched LACP settings or VLAN mappings can create loops or cause packet loss, as noted inArista M-LAG Documentation. These problems can persist even when the system appears normal, making consistency checks critical for troubleshooting and O&M.

Conclusion: True.

Option C: If Type 2 configurations of the two M-LAG member devices are inconsistent, the M-LAG running status may be abnormal. Compared with Type 1 configuration problems, Type 2 configuration problems are more likely to be detected and have less impact on the network.

Evaluation: This statement is true. Type 2 (common) configurations, such as QoS or STP settings, are less critical but can still affect network performance. According toHuawei M-LAG Best Practices, Type 2 inconsistencies are often detected during consistency checks but have a lower impact on M-LAG operation compared to Type 1 issues. They are also more likely to be flagged during monitoring, as they are less severe and easier to resolve.

Conclusion: True.

Option D: If Type 2 configurations of the two M-LAG member devices are inconsistent, an alarm that indicates key and common configuration inconsistencies is generated.

Evaluation: This statement is false. While Type 2 (common) configuration inconsistencies are detected during consistency checks, they do not typically triggeralarms, especially alarms that specifically indicate both key and common configuration inconsistencies. According toHuawei M-LAG Configuration GuideandArista M-LAG Documentation, Type 2 inconsistencies may be logged or reported in system logs but are not severe enough to generate critical alarms unless they significantly impact network operation. Alarms are more commonly associated with Type 1 (key) configuration inconsistencies, as they pose a higher risk to M-LAG functionality.

Conclusion: False.

VXLAN (Virtual Extensible LAN) tunnels are used to encapsulate Layer 2 traffic over a Layer 3 network, a key feature in Huawei’s data center solutions. The endpoints of a VXLAN tunnel are VXLAN Tunnel Endpoints (VTEPs), identified by their IP addresses.

Tunnel Identification:A VXLAN tunnel is uniquely identified by the pair of VTEP IPaddresses (local and remote), along with the VNI (VXLAN Network Identifier). This pair ensures the tunnel is specific to the communication path between the two VTEPs.

Tunnel Establishment:During setup, VTEPs exchange information to learn each other’s IP addresses. This can occur manually (static configuration) or dynamically (e.g., via BGP EVPN). The underlay network must provide Layer 3 reachability between the VTEP IP addresses, typically using routing protocols (e.g., OSPF, BGP) to ensure IP connectivity.

Reachability Condition:If the local and remote VTEP IP addresses are reachable at Layer 3, the tunnel can be established, allowing encapsulation and decapsulation of VXLAN traffic. This is a fundamental requirement in Huawei’s VXLAN implementation.

The statement isTRUE (A)because a VXLAN tunnel’s identification and establishment depend on reachable VTEP IP address pairs at Layer 3.References:Huawei HCIP-Data Center Network Training – VXLAN Tunneling; CloudFabric VXLAN Deployment Guide.

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 withType 5routes. 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 is5.References:Huawei HCIP-Data Center Network Training – BGP EVPN Routes; CloudFabric EVPN Configuration Guide.

A vNIC (virtual Network Interface Card) is a software-emulated network interface used by virtual machines to communicate over a virtual or physical network. The statement’s reference to “bit stream mode” is ambiguous but likely implies raw, low-level bit transmission without higher-layer processing.

vNIC Functionality:A vNIC operates at a higher abstraction level than physical NICs. It interfaces with the hypervisor’s virtual switch (e.g., Open vSwitch in Huawei environments) and handles data in frames or packets (e.g., Ethernet frames), not just raw bit streams. The hypervisor or host NIC handles the physical bit stream transmission.

Data Transmission:vNICs support various modes depending on configuration (e.g., VirtIO, SR-IOV passthrough), transmitting structured data (frames/packets) rather than solely raw bits. Bit stream transmission is a physical-layer task, not the vNIC’s sole mode.

Thus, the statement isFALSE (B)because a vNIC does not transmit dataonlyin bit stream mode; it handles higher-level data structures, with bit-level transmission managed by underlying hardware.References:Huawei HCIP-Data Center Network Training – Virtualization Networking; FusionCompute Networking Guide.

In Huawei’s CloudFabric Solution,SecoManager(Security Manager) andiMaster 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 isFALSE (B)because interconnection is automated, not manual.References:Huawei CloudFabric Data Center Network Solution – Component Integration; HCIP-Data Center Network Training – SDN Deployment.

EVPN (Ethernet VPN) is a control plane technology used with VXLAN in Huawei’s data center networks to provide Layer 2 and Layer 3 connectivity. EVPN routes are advertised using BGP, with different types serving specific purposes. Type 3 routes (Inclusive Multicast Ethernet Tag routes) are used for multicast or BUM (Broadcast, Unknown Unicast, Multicast) traffic handling in VXLAN networks.

MPLS Label Field:In MPLS (Multiprotocol Label Switching), the label field is used to identify the forwarding equivalence class (FEC) or virtual circuit. In EVPN with VXLAN, MPLS labels can be used in underlay networks, but VXLAN itself relies on a VNI (VXLAN Network Identifier) in the VXLAN header for overlay segmentation.

Layer 3 VNI:A Layer 3 VNI is associated with inter-subnet routing in EVPN, typically carried in Type 5 routes (IP Prefix routes) for Layer 3 forwarding. Type 3 routes, however, focus on multicast distribution and carry a Layer 2 VNI or multicast group information, not a Layer 3 VNI.

MPLS Label in Type 3 Routes:The MPLS label in Type 3 routes, if used, identifies the VXLAN tunnel or multicast group, not a Layer 3 VNI. The Layer 3 VNI is specific to Type 5 routes for routing between subnets, not Type 3’s multicast focus.

Thus, the statement isFALSE (B)because the MPLS Label field in EVPN Type 3 routes does not carry a Layer 3 VNI; it relates to Layer 2 multicast or tunnel identification.References:Huawei HCIP-Data Center Network Training – EVPN and VXLAN; CloudFabric EVPN Configuration Guide.

VXLAN (Virtual Extensible LAN) is a network overlay technology that encapsulates Layer 2 Ethernet frames within UDP packets to extend Layer 2 networks over Layer 3 infrastructure, widely used in Huawei’s CloudFabric data center solutions. The encapsulation process, often referred to as "MAC-in-UDP," involves wrapping the original Ethernet frame (including MAC addresses) inside a UDP packet.

UDP Encapsulation:The VXLAN header follows the UDP header, and the destination UDP port number identifies VXLAN traffic. The Internet Assigned Numbers Authority (IANA) has officially assignedUDP port 4789as the default destination port for VXLAN.

Options Analysis:

A. 4787:This is not a standard VXLAN port and is not recognized by IANA or Huawei documentation.

B. 4789:This is the correct and widely adopted destination port for VXLAN, as specified in RFC 7348 and implemented in Huawei’s VXLAN configurations.

C. 4790:This port is not associated with VXLAN and is unused in this context.

D. 4788:This is not a standard VXLAN port; it may be confused with other protocols but is not correct for VXLAN.

Thus, the destination port number used during UDP encapsulation in VXLAN isB (4789), aligning with Huawei’s VXLAN implementation standards.References:Huawei CloudFabric Data Center Network Solution – VXLAN Configuration Guide; RFC 7348 – Virtual eXtensible Local Area Network (VXLAN).

In Huawei’s CloudFabric Solution, Virtual Private Clouds (VPCs) enable isolated network environments, and interworking scenarios involve traffic between VPCs. The statement claims that traffic is checked and filtered only by the firewall in the source or destination VPC. Let’s evaluate:

VPC Interworking:Traffic between VPCs can be routed via a gateway (e.g., a Layer 3 gateway or centralized router) and may involve multiple security checkpoints depending on the design. Firewalls can be deployed in the source VPC, destination VPC, or a centralized location (e.g., a service chain or border gateway).

Firewall Role:The statement implies exclusivity (only one firewall), but in practice, traffic may be filtered by firewalls at both ends, a centralized firewall, or additional security devices (e.g., VAS nodes) in the path. For example, inter-VPC traffic might pass through a firewall in the source VPC for egress filtering and another in the destination VPC for ingress filtering, or a shared firewall in a hub-and-spoke model. Huawei’s security architecture (e.g., with SecoManager) supports distributed or centralized filtering, not limited to a single VPC’s firewall.

The statement isFALSE (B)because traffic is not restricted to being checked and filtered only by the firewall in the source or destination VPC; multiple firewalls or security devices may be involved.References:Huawei CloudFabric Data Center Network Solution – VPC Interworking; HCIP-Data Center Network Training – Security Design.

In Huawei’s spine-leaf DCN architecture, nodes have distinct roles:

A. Spine:The spine nodes form the backbone of the data center, providing high-speed IP forwarding between leaf nodes. They handle east-west traffic with non-blocking connectivity, making them the core backbone nodes.Correct.

B. DC1 leaf:This is not a standard node type; it may be a typo or misnomer. Leaf nodes connect to endpoints, not act as backbones.Incorrect.

C. Service leaf:Service leaf nodes connect to internal services (e.g., servers), not the backbone, focusing on access rather than high-speed forwarding.Incorrect.

D. Border leaf:Border leaf nodes connect to external networks, handling routing, not serving as the internal backbone.Incorrect.

Thus, the answer isA (Spine).References:Huawei CloudFabric Data Center Network Solution – Spine-Leaf Architecture; HCIP-Data Center Network Training – Node Roles.

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,Dis not a possible cause of the fault.References:Huawei CloudFabric Data Center Network Solution – Troubleshooting Guide; HCIP-Data Center Network Training – VXLAN Connectivity.

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 traditionalVLANs (4096 limit).TRUE.

Thus,Ais the false statement because a VTEP, not a VNI, is the tunnel endpoint that performs encapsulation.References:Huawei CloudFabric Data Center Network Solution – VXLAN Overview; HCIP-Data Center Network Training – VXLAN Protocol.

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.References:Huawei HCIP-Data Center Network Training – OpenStack Architecture; OpenStack Official Documentation – Service Overview.

The underlay network in Huawei’s DCNs (e.g., CloudFabric) uses routing protocols like OSPF or BGP. Let’s evaluate each statement:

A. OSPF is recommended for small and midsize DCNs, and EBGP is recommended for large and midsize networks:This is true. OSPF suits smaller networks (<300 switches), while EBGP is better for large networks (>300 switches) due to scalability.TRUE.

B. When OSPF is used on the underlay network, only single-area OSPF can be deployed:This is false. Multi-area OSPF can be deployed to manage larger networks, reducing routing table size and improving stability, a common practice in Huawei DCNs.FALSE.

C. Compared with OSPF, EBGP involves fewer calculations and offers better scalability:This is true. EBGP’s path-vector nature requires fewer computational resources than OSPF’s link-state calculations and scales better with large topologies.TRUE.

D. When EBGP is used on the underlay network, each group of active-active leaf nodes is deployed in an AS:This is true. In EBGP designs, active-active leaf nodes (e.g., M-LAG) are typically in the same Autonomous System (AS) to simplify routing, using iBGP or route reflectors.TRUE.

Thus,Bis the false statement because multi-area OSPF is supported, not just single-area.References:Huawei CloudFabric Data Center Network Solution – Underlay Routing; HCIP-Data Center Network Training – OSPF and BGP Design.