Huawei’s iMaster NCE-Fabric is an SDN controller for the CloudFabric data center network solution, providing network management and automation. The rollback feature allows administrators to revert configuration changes to previous states in case of errors. According to Huawei’s documentation, iMaster NCE-Fabric supports four rollback levels , enabling the system to store and restore up to four previous configuration versions. This ensures flexibility in undoing changes during network management tasks like upgrades or policy adjustments.

Options Analysis:

A. 3: Incorrect, as it underestimates the supported levels.

B. 4: Correct, aligning with Huawei’s specified rollback capability.

C. 2: Incorrect, as it is fewer than the supported levels.

D. 1: Incorrect, as it limits rollback to a single state, which is insufficient for complex management.

Thus, the answer is B (4) . References: Huawei CloudFabric Data Center Network Solution – iMaster NCE-Fabric Features; HCIP-Data Center Network Training – SDN Controller Management.

The tenant service model in Huawei’s data center networks (e.g., CloudFabric with SDN) organizes resources for multi-tenancy. Let’s evaluate each statement:

A. A tenant can apply for independent compute, storage, and network resources: This is true. Tenants in a multi-tenant environment can request isolated compute (VMs), storage (volumes), and network (VLANs/VXLAN VNIs) resources, a core feature of Huawei’s tenant isolation model. TRUE.

B. One logical router is mapped to one VRF: This is true. A Virtual Routing and Forwarding (VRF) instance is associated with a logical router to provide isolated Layer 3 routing for a tenant, a standard practice in Huawei’s network virtualization. TRUE.

C. An EPG can have only one subnet: This is false. An Endpoint Group (EPG) in Huawei’s ACI-like models can span multiple subnets, grouping endpoints (e.g., VMs) based on policies, not limited to a single subnet. FALSE.

D. A subnet supports the access of only one VM: This is false. A subnet can support multiple VMs, as it defines an IP address range for a network segment, not a one-to-one VM mapping. FALSE.

Thus, A and B are true statements about the tenant service model. References: Huawei CloudFabric Data Center Network Solution – Tenant Model; HCIP-Data Center Network Training – Multi-Tenancy.

IP address planning is critical in Huawei’s CloudFabric data center networks to ensure scalability and efficiency. Let’s evaluate each statement:

A. Service addresses refer to the IP addresses of servers, hosts, and gateways: This is true. Service addresses are assigned to endpoints (servers, hosts) and gateways, distinguishing them from management or interconnection IPs in DC planning. TRUE.

B. IP addresses with a 24-bit mask are recommended for use as interconnection IP addresses: This is false. A 24-bit mask (/24) is typically used for service subnets, while interconnection IPs (e.g., between spine and leaf) often use smaller masks (e.g., /31 or /30) to conserve addresses and align with point-to-point links. FALSE.

C. IP addresses must be contiguous. The routes with contiguous IP addresses can be summarized easily on a hierarchical network: This is false. Contiguity is desirable for summarization but not mandatory; non-contiguous blocks can still be managed with proper routing design (e.g., using BGP). FALSE.

D. IP address allocation should be simple and easy to manage, reflect network layers, and simplify network management and network expansion: This is true. Huawei recommends structured allocation (e.g., by layer or function) to streamline management and support future growth. TRUE.

Thus, A and D are true statements about IP address planning. References: Huawei CloudFabric Data Center Network Solution – IP Planning; HCIP-Data Center Network Training – Address Management.

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. References: Huawei CloudFabric Data Center Network Solution – Intelligent O & M; HCIP-Data Center Network Training – Troubleshooting Dimensions.

Multi-Chassis Link Aggregation Group (M-LAG) is a high-availability technology on Huawei CloudEngine (CE) series switches, where two switches appear as a single logical device to downstream devices. The peer-link between the M-LAG peers synchronizes critical information to ensure seamless failover if one device fails. Let’s evaluate the entries:

A. MAC Address Entries: MAC address tables map device MACs to ports. In M-LAG, synchronizing MAC entries ensures that both switches know the location of connected devices. If one switch fails, the surviving switch can forward Layer 2 traffic without relearning MAC addresses, preventing disruptions. Required.

B. Routing Entries: Routing entries (e.g., OSPF or BGP routes) are maintained at Layer 3 and typically synchronized via routing protocols, not M-LAG peer-link packets. M-LAG operates at Layer 2, and while Layer 3 can be overlaid (e.g., with VXLAN), routing table synchronization is not a standard M-LAG requirement. Not Required.

C. IGMP Entries: IGMP (Internet Group Management Protocol) entries track multicast group memberships. While useful for multicast traffic, they are not critical for basic unicast traffic forwarding in M-LAG failover scenarios. Huawei documentation indicates IGMP synchronization is optional and context-specific, not mandatory for general traffic continuity. Not Required.

D. ARP Entries: ARP (Address Resolution Protocol) entries map IP addresses to MAC addresses, crucial for Layer 2/Layer 3 communication. Synchronizing ARP entries ensures the surviving switch can resolve IP-to-MAC mappings post-failover, avoiding ARP flooding or traffic loss. Required.

Thus, A (MAC address entries) and D (ARP entries) are essential for M-LAG synchronization to maintain traffic forwarding during failover, per Huawei CE switch M-LAG design. References: Huawei CloudEngine Series Switch Configuration Guide – M-LAG Section; HCIP-Data Center Network Training – High Availability Technologies.

The physical architecture of a server refers to the tangible and low-level components that constitute the server itself, distinct from logical or software layers. Let’s evaluate each option:

A. Application: Applications are software running on top of an operating system or virtual machine, not part of the server’s physical architecture. They belong to the logical or user layer, not the physical structure. Not Included.

B. VMmonitor (Hypervisor): Assuming “VMmonitor” refers to a hypervisor (e.g., KVM or Xen), it’s a software layer, but in Type-1 hypervisor scenarios, it runs directly on hardware, managing VMs. In Huawei’s context, it’s considered part of the server’s operational architecture when deployed physically. Included.

C. OS (Operating System): The OS (e.g., Linux, Windows) runs directly on server hardware or within a VM. In bare-metal servers, it’s a core component of the physical deployment. Included.

D. Hardware: Hardware (e.g., CPU, RAM, NICs, disks) is the foundational physical architecture of a server, providing the physical resources for all operations. Included.

Thus, A (Application) is not part of the physical architecture, as it’s a higher-level software entity, not a physical component. References: Huawei HCIP-Data Center Network Training – Server Architecture; FusionCompute Physical Architecture Overview.

Huawei’s CloudFabric Solution, managed by iMaster NCE-Fabric, provides robust Operations and Maintenance (O & M) capabilities. Let’s evaluate each option:

A. Multi-path detection: This is true. CloudFabric supports multi-path detection (e.g., using ECMP) to verify load balancing and path diversity in the network. TRUE.

B. Network connectivity detection, such as IP ping and MAC ping: This is true. Tools like IP ping and MAC ping are supported for troubleshooting connectivity between devices and endpoints. TRUE.

C. Single-path detection: This is false. While multi-path detection is supported, single-path detection is not a distinct O & M function; connectivity checks typically involve multiple paths or end-to-end verification. FALSE.

D. Visualization of entries (MAC/IP) on logical routers and switches: This is true. CloudFabric provides visualization of MAC and IP entries on logical network elements, aiding in network management and troubleshooting. TRUE.

Thus, A, B, and D are supported O & M functions. References: Huawei CloudFabric Data Center Network Solution – O & M Features; HCIP-Data Center Network Training – Network Operations.

Zero Touch Provisioning (ZTP) in Huawei’s CloudFabric automates device setup using DHCP. Let’s evaluate each option:

A. Default gateway address: This is true. DHCP can deliver the default gateway address to configure routing for the device. TRUE.

B. SFTP server address: This is false. SFTP server addresses are not standard DHCP options; they may be configured manually or via other protocols (e.g., TFTP for boot files). FALSE.

C. DNS server address: This is true. DHCP can provide DNS server addresses (Option 6) for name resolution during ZTP. TRUE.

D. Temporary management IP address: This is true. DHCP assigns temporary IPs (e.g., Option 50) for management during initial provisioning in ZTP. TRUE.

Thus, A, C, and D can be delivered by a DHCP server in ZTP. References: Huawei CloudFabric Data Center Network Solution – ZTP Configuration; HCIP-Data Center Network Training – ZTP Process.

In Huawei’s CloudFabric computing scenario, VM service traffic involves virtualized environments with VXLAN overlays and traditional VLANs. Let’s evaluate each statement:

A. Traffic inside a fabric is VXLAN encapsulated: This is true. Within a CloudFabric network, VXLAN encapsulation is used to transport traffic across the fabric, enabling overlay networking for VMs. TRUE.

B. Inter-VPC traffic must pass through the firewall: This is false. Inter-VPC (Virtual Private Cloud) traffic can be routed directly between VPCs using a gateway or router (e.g., with EVPN Type 5 routes) without necessarily passing through a firewall, depending on security policies. Firewalls are optional for inter-VPC traffic, not mandatory. FALSE.

C. Traffic between VAS devices and service leaf nodes is VLAN encapsulated: This is true. Value-Added Services (VAS) devices (e.g., load balancers) often connect to service leaf nodes using VLAN encapsulation, especially in traditional or hybrid deployments. TRUE.

D. Traffic between vSwitches on virtual servers and server leaf nodes is VLAN encapsulated: This is true. Traffic from virtual switches (vSwitches) on hypervisors to physical server leaf nodes typically uses VLAN encapsulation over the physical NICs, before VXLAN overlay if applicable. TRUE.

Thus, B is the false statement because inter-VPC traffic does not always require a firewall. References: Huawei CloudFabric Data Center Network Solution – Traffic Engineering; HCIP-Data Center Network Training – VM Traffic.

Link aggregation, often implemented using Link Aggregation Control Protocol (LACP) on Huawei CloudEngine (CE) series switches, combines multiple physical links into a single logical link to enhance network performance and resilience. The primary advantages include:

Load Balancing Supported (B): Link aggregation distributes traffic across multiple links based on hashing algorithms (e.g., source/destination IP or MAC), improving load distribution and preventing any single link from becoming a bottleneck.

Increased Bandwidth (C): By aggregating multiple links (e.g., 1 Gbps ports into a 4 Gbps logical link), the total available bandwidth increases proportionally to the number of links.

Improved Reliability (D): If one link fails, traffic is automatically redistributed to the remaining links, ensuring continuous connectivity and high availability.

However, Improved Forwarding Performance of Switches (A) is not a direct advantage. Forwarding performance relates to the switch’s internal packet processing capabilities (e.g., ASIC performance, forwarding table size), which link aggregation does not inherently enhance. While it optimizes link utilization, it doesn’t improve the switch’s intrinsic forwarding rate or reduce latency at the hardware level. This aligns with Huawei’s CE series switch documentation, where link aggregation is described as enhancing bandwidth and reliability, not the switch’s core forwarding engine. References: Huawei CloudEngine Series Switch Configuration Guide – Link Aggregation Section.