H12-811_V2.0 Huawei HCIA-Datacom V2.0 Free Practice Exam Questions (2026 Updated)

When a switch receives an untagged frame from a user host on an access interface , it associates that frame with the VLAN configured on the interface. In this scenario, PC1 and PC2 are in VLAN 10, and GE1/0/2 is an access interface in VLAN 10. After SW1 receives the frame from PC1, it internally associates the frame with VLAN 10 , so option A is correct in the practical VLAN-processing sense used in HCIA-Datacom questions.

When the frame is forwarded out an access interface toward PC2, the switch sends it without a VLAN tag , because end hosts normally do not process 802.1Q tags. Therefore, option D is correct. Option B is incorrect because both hosts are in the same VLAN and can communicate normally; SW1 does not discard the return traffic for that reason. Option C is not correct in the standard VLAN switching model used by Huawei training, because the switch performs forwarding based on VLAN membership and internally processes the frame as belonging to VLAN 10. This question mainly checks understanding of access/trunk behavior and tag handling on ingress and egress.

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To check OSPF-learned routes in the global IP routing table , the correct command is display ip routing-table protocol ospf , so option A is correct. This command filters the routing table and shows only the routes whose source protocol is OSPF. It is especially useful when verifying whether OSPF-learned routes have been successfully installed into the forwarding table after neighbor establishment and LSDB calculation.

Option B , display ospf peer, is used to check OSPF neighbor information and adjacency states, not the routing table. Option C , display ospf interface, shows OSPF-related parameters on interfaces such as timers, network type, and cost. Option D , display ospf routing, displays OSPF route information maintained by the OSPF process itself, but the question specifically asks about routes in the global routing table , which is the RIB used for actual forwarding decisions. HCIA-Datacom distinguishes between protocol-specific route information and the final routing table seen by the device. Understanding this distinction helps engineers verify whether a protocol has only learned topology information or has actually produced usable forwarding entries.

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A router works mainly at the network layer . When it receives a frame, it removes the Layer 2 header and trailer, examines the destination IP address in the Layer 3 header, consults the routing table, selects the outgoing interface, and then re-encapsulates the packet into a new Layer 2 frame for the next hop. Therefore, statement B is true and is not part of the answer.

Statement A is false because the router does not create a new destination IP address during normal forwarding. The source and destination IP addresses remain unchanged end to end unless special functions such as NAT are used. Statement C is false because routing-table lookup is based on the destination IP address, not on TCP or UDP port numbers. Statement D is also false because normal IP routing does not inspect application-layer content to determine the outgoing interface. That decision is made from the network-layer destination address and the routing table. This question tests the layered forwarding logic of routers in TCP/IP networks.

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Comprehensive and Detailed 150 to 200 words of Explanation From Datacom knowledge:

The false statement is B . From the AAA configuration output, the value of Remote-admin-user block time is clearly shown as 5 Min(s) , which means the account lockout duration is 5 minutes , not 30 minutes.

Option A is true because Remote-admin-user block retry-time : 3 indicates that after 3 consecutive authentication failures , the account will be blocked. Option C is also true because the displayed Domain Name Delimiter is @ , which is the separator used in usernames such as user@huawei.com. Option D is true as well because the output shows Local-user : total: 512 used: 2 , meaning that the device supports a maximum of 512 local users , and currently 2 local users have been created.

This question checks the ability to correctly read AAA configuration output on Huawei devices. In HCIA-Datacom knowledge, it is important to distinguish between retry interval , retry count , and block time , because these values represent different security control parameters and are often confused during troubleshooting or configuration review.

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This statement is false . In classic STP, when a non-root switch detects a topology change, it does not continuously send configuration BPDUs upstream to notify the root bridge. Instead, it sends a Topology Change Notification (TCN) BPDU toward the root bridge through its root port. Each upstream switch acknowledges the TCN and forwards it further until it reaches the root bridge.

After the root bridge receives the topology change notification, the root bridge sets the Topology Change (TC) flag in its configuration BPDUs, and those configuration BPDUs are then propagated throughout the network. Therefore, topology-change notification and normal configuration BPDU transmission are different functions. The statement is wrong because it confuses TCN BPDUs with configuration BPDUs , and also inaccurately describes the notification behavior. HCIA-Datacom requires learners to distinguish between these BPDU types and understand how STP reacts to topology changes by accelerating MAC address aging and informing the network through the root bridge. This process helps the Layer 2 topology converge and reduces long-lasting forwarding inconsistencies after a link or port-state change.

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This statement is false . In Layer 3 in-path WLAN networking , the WAC and Fit APs communicate over Layer 3, which means the APs must discover the WAC through methods that are valid across Layer 3 boundaries. Broadcast is a Layer 2 mechanism and cannot normally be used for WAC discovery across Layer 3 networks. Therefore, saying that APs can obtain the WAC address through broadcast or DHCP in this scenario is incorrect.

In Huawei WLAN deployments, Fit APs can commonly discover the WAC address through methods such as DHCP option-based discovery , DNS , or preconfigured controller information, depending on the deployment model and product features. Because the WAC and AP are not in the same Layer 2 broadcast domain in Layer 3 in-path networking, broadcast discovery is not the standard mechanism here. HCIA-Datacom stresses the difference between Layer 2 direct discovery and Layer 3 discovery methods because this affects initial AP registration, CAPWAP establishment, and troubleshooting when APs fail to go online. Understanding the discovery mechanism is essential when planning IP addressing, DHCP options, and controller placement in enterprise WLAN designs.

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This statement is true . Traditional VLANs use a 12-bit VLAN ID , which means that only about 4094 usable VLANs are available. In modern data centers, especially in cloud and virtualization environments, that scale is often insufficient because a very large number of tenants, services, and virtual machines need isolated network segments.

VXLAN addresses this limitation by introducing the VNI (VXLAN Network Identifier) , which is 24 bits long. This allows support for up to about 16 million logical segments , greatly expanding the number of isolated Layer 2 networks that can be created across an IP underlay. Because of this, VXLAN is widely used in modern data centers to provide scalable tenant isolation, flexible service deployment, and large Layer 2 extension across physical boundaries. HCIA-Datacom highlights VXLAN as a key overlay technology that solves the VLAN scale problem in virtualized data center environments. It allows a much larger number of VMs and tenants to be isolated than traditional VLAN-based solutions can support, making it essential for modern cloud-oriented and large-scale data center networking.

Several upper-layer management and file transfer protocols use SSH as their secure transport foundation. SFTP is the SSH File Transfer Protocol and operates over SSH, making option C correct. STelnet is secure Telnet implemented over SSH, so option D is also correct. NETCONF commonly uses SSH as its transport protocol for secure configuration management and device orchestration, making option B correct as well.

Option A, DNS, does not use SSH as its normal transport protocol. Traditional DNS operates over UDP or TCP port 53, depending on the query or transfer type. Although DNS security extensions and encrypted DNS variants exist, they are not based on SSH. HCIA-Datacom emphasizes the role of SSH in secure network management because it replaces insecure plaintext protocols and provides confidentiality, integrity, and authentication. In practical Huawei enterprise deployments, SSH-based protocols are widely used for interactive device login, automated configuration delivery, and secure file operations. This question tests recognition of management protocols that inherit SSH’s secure channel rather than protocols that operate independently at the application layer.

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After STP convergence, only ports in the forwarding state participate in active traffic forwarding, while redundant ports may be placed into the blocking or discarding state to eliminate loops. According to the topology and STP role election shown in the question, the valid forwarding path from SW1 to SW4 is SW1 → SW3 → SW4, so option B is correct.

This means that the direct alternative path or the path through SW2 is not the active spanning-tree forwarding path after election and state transition. STP selects paths based on the root bridge, path cost, bridge ID, and port ID. Once the root bridge and port roles are determined, some links remain active and others are blocked to ensure a loop-free Layer 2 topology. HCIA-Datacom emphasizes that the resulting forwarding topology is a tree, not a mesh, even if the physical topology contains redundant links. Understanding the actual forwarding path after STP convergence is important for troubleshooting connectivity, predicting traffic behavior, and verifying whether bridge priority and path-cost settings have produced the intended design outcome in campus switching networks.

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All four options are possible causes of FTP login failure, so the correct answer is A, B, C, and D.

Option A is correct because if the FTP server function is not enabled on the Huawei device, the device cannot provide FTP services and the client cannot log in. Option B is also correct because if the authorized directory is not specified for the FTP user, the user may not be able to complete login or access file services properly, depending on the FTP user configuration requirements. Option C is correct because an FTP user account must be configured with the required username and password; otherwise, authentication cannot succeed. Option D is also correct because if the network between the FTP client and the device is unreachable, the client cannot establish the FTP connection at all.

In HCIA-Datacom troubleshooting, FTP login failure is usually checked from four aspects: service enablement, user configuration, permission or directory authorization, and network connectivity. This question tests standard remote maintenance troubleshooting logic for file transfer services on Huawei network devices.

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Duplicate Address Detection ( DAD ) is an IPv6 mechanism used to verify that a unicast address is not already in use before the address is assigned to an interface. DAD is implemented using Neighbor Solicitation (NS) and Neighbor Advertisement (NA) messages, which are part of the ICMPv6 Neighbor Discovery protocol. Therefore, options A and D are correct.

When a host wants to verify a tentative IPv6 address, it sends an NS message for that address. If another node on the link is already using that address, that node responds with an NA message, indicating the address is duplicated and cannot be assigned. If no NA is received within the required period, the host assumes the address is unique and can use it. Options B and C are incorrect because Router Solicitation (RS) and Router Advertisement (RA) are used for router discovery, prefix advertisement, and stateless address autoconfiguration, not for DAD itself. HCIA-Datacom emphasizes the distinction between Neighbor Discovery functions, including address resolution, next-hop reachability, router discovery, and duplicate address detection in IPv6 networks.

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This statement is false because the receiver is one of the fundamental elements of communication. In basic communication theory, a complete communication process requires at least four essential elements: the sender , the information or message content , the transmission medium or channel , and the receiver . If the receiver is missing, communication cannot be completed because there is no endpoint to accept, interpret, or respond to the transmitted information.

In datacom networks, this concept maps directly to real networking scenarios. A source host generates data, the data is carried over some medium such as copper, fiber, or wireless, and a destination host receives the data. Network devices such as switches and routers assist the forwarding process, but the fundamental communication model still includes both communicating endpoints. HCIA-Datacom emphasizes the complete sender-to-receiver process when introducing network communication basics, protocol encapsulation, and forwarding. Therefore, excluding the receiver from the communication elements is conceptually incorrect. The correct understanding is that sender, receiver, information content, and channel together form the essential basis of communication.

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