Huawei H12-811_V2.0 - HCIA-Datacom V2.0

On Huawei devices, the undo command is used to remove a previously applied configuration, disable a function, or restore a parameter to its default state. In option B, undo ip address is a valid interface-view command that removes the IP address configured on the interface. In option C, undo portswitch is also a valid interface command on switch interfaces that converts a Layer 2 interface into a Layer 3 interface when supported by the device. In option D, undo sysname restores the device name to the default hostname, which is valid in system view.

Option A is incorrect because system-view is a command used to enter system view from user view, but undo system-view is not a valid command for exiting that view. Exiting system view is done with commands such as quit, return, or by using shortcut keys. This question checks the understanding that undo only applies to configurable features and parameters, not to view-switching commands in the CLI hierarchy.

Huawei ' s HCIA-Datacom WLAN troubleshooting material identifies several causes of wireless station access failures.

Option A is correct because excessive channel utilization causes contention, retransmissions, and degraded wireless communication. The training material indicates that channel utilization exceeding approximately 85% can prevent STAs from accessing the network reliably.

Option B is correct because the WAC can deny wireless client access through blacklist-based admission control.

Option C is correct because network faults may prevent DHCP messages from reaching their destination, leaving the STA without a valid IP address and preventing successful network connectivity.

Option D is correct because a defective wireless network adapter can prevent the STA from establishing or maintaining wireless communication.

Troubleshooting should distinguish failures during scanning, authentication, association, and IP address allocation.

Therefore, all four options represent possible causes.

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PC1 and PC2 are in different VLANs on SW1, while PC3 is in VLAN 4 on SW2. To allow traffic from VLAN 2 and VLAN 3 users to reach PC3 through the inter-switch link, SW1 must be able to send frames from PC1 and PC2 toward SW2 in a form that SW2 can place into VLAN 4.

Option B is valid because a hybrid interface on SW1 can send frames from VLAN 2 and VLAN 3 untagged, and setting the PVID to VLAN 4 allows untagged inbound frames on the peer side to be associated appropriately when matched with the SW2 configuration. Option C is also valid because configuring SW2’s GE1/0/3 as a trunk allowing VLAN 4 and setting its PVID to VLAN 4 means untagged frames arriving from SW1 are treated as belonging to VLAN 4 and can then be forwarded to PC3 through its access interface.

Option A is incomplete because only configuring SW2 does not solve the VLAN handling on SW1. Option D is incorrect because a trunk on SW1 would send VLAN 2 and VLAN 3 frames tagged, which would not match the VLAN 4-only expectation on SW2 in this scenario.

All four configured static routes have the same destination prefix, 20.0.0.0/30, and the question states that every next hop is reachable. Huawei route selection first considers route preference when choosing among routes from the same or different route sources. For static routes, a smaller preference value means a higher priority. The four preferences shown are 60 for next hop 10.1.1.2, 70 for 10.1.2.2, 100 for 10.1.3.2, and 50 for 10.1.4.2. Because 50 is the smallest preference, the route through 10.1.4.2 is selected as the active route in the IP routing table. The other configured static routes can remain as lower-priority alternatives and may become active if the preferred route becomes invalid, depending on reachability and configuration. Equal-cost load balancing would require routes with the same relevant preference and cost after route selection. That is not the case here. Therefore, the next hop of the selected route to 20.0.0.0/30 is 10.1.4.2, making option A correct.

Wi-Fi 7 supports operation in the 2.4 GHz, 5 GHz, and 6 GHz frequency bands, so options A, C, and D are correct. These three bands together provide flexible coverage and capacity options. The 2.4 GHz band offers better propagation and wider coverage, while the 5 GHz and 6 GHz bands provide more channels, higher capacity, and better support for high-speed, low-latency services.

Option B, 9.6 GHz, is incorrect because it is not a Wi-Fi 7 operating band. HCIA-Datacom WLAN content highlights Wi-Fi 7 as a major advancement in wireless performance, bringing improvements in throughput, channel usage, spectrum efficiency, and latency characteristics. The addition and use of the 6 GHz band is especially important because it expands available spectrum resources and helps reduce contention in dense wireless environments. In practical enterprise WLAN design, understanding supported frequency bands is essential for channel planning, interference control, device compatibility assessment, and service optimization. This question checks whether the learner can correctly identify the standard operating bands used by modern Wi-Fi 7 networks.

The normal DHCPv4 address-allocation exchange is commonly summarized as DORA: Discover, Offer, Request, and Acknowledge. A DHCP client that needs configuration begins by sending DHCPDISCOVER to locate available DHCP servers. A server responds with DHCPOFFER, proposing an address and other parameters. The client then sends DHCPREQUEST to indicate the offered address and server it has selected. Finally, the selected DHCP server sends DHCPACK to confirm the lease and deliver the final configuration. Therefore, DHCPDISCOVER and DHCPREQUEST are client-originated messages in the standard allocation process, while DHCPOFFER and DHCPACK are server-originated messages. DHCP also defines other messages for lease renewal, decline, release, and negative acknowledgment, but those are not among the answer choices. For the options provided, A, DHCPACK, and D, DHCP OFFER, are the messages sent by a DHCPv4 server. The verified answer is A and D. This server-versus-client message direction is fundamental when interpreting DHCP packet captures and troubleshooting address-allocation failures on enterprise campus access networks.

This statement is false because although Area 0 is indeed the backbone area, the statement about the area ID range is incorrect. In OSPF, the area ID is a 32-bit value, which can be represented either in decimal format or in IPv4 address format such as 0.0.0.0. It is not limited to the numeric range 0 to 255.

For example, an area can be configured as 0, 1, 100, or in dotted-decimal form such as 0.0.0.1 or 0.0.0.10, depending on implementation and configuration style. HCIA-Datacom teaches that OSPF uses hierarchical area design to improve scalability, reduce SPF calculation scope, and optimize LSA flooding. The backbone area, which is Area 0, serves as the transit area connecting all non-backbone areas in a standard OSPF design. Therefore, the second part of the statement is correct, but the first part is wrong, making the entire statement false. This question tests whether the learner understands both the function of Area 0 and the actual format of OSPF area identifiers.

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.

The topology contains three Layer 3 interconnection VLANs: VLAN 12 between Core1 and ACC1, VLAN 13 between Core1 and ACC2, and VLAN 23 between ACC1 and ACC2. OSPF is enabled across the campus, while STP still controls Layer 2 forwarding on the VLAN links. If ACC2 GE1/0/3 is an alternate port, STP blocks service forwarding on the ACC1-ACC2 path. As a result, OSPF Hello packets cannot be exchanged across that blocked Layer 2 path and ACC1 and ACC2 cannot establish an OSPF neighbor relationship on VLAN 23, so C is true. Core1 still has routes for all three interconnection networks: VLAN 12 and VLAN 13 are directly connected, and information for VLAN 23 can be learned through OSPF from the access devices, making B true. Statement A is incorrect because ACC1 already has VLANIF 23 as a directly connected network rather than needing to learn that same connected segment through OSPF. Statement D is also false: STP can still be relevant on Layer 2 VLAN links even in a campus using Layer 3 routing.

A /27 subnet mask is 255.255.255.224, which means each subnet contains 32 IP addresses. The subnet increments in blocks of 32 in the last octet: 0, 32, 64, 96, 128, 160, 192, 224. The address 192.168.1.200/27 belongs to the subnet 192.168.1.192/27.

For this subnet, the network address is 192.168.1.192, the broadcast address is 192.168.1.223, and the valid host range is from 192.168.1.193 to 192.168.1.222. Therefore, 192.168.1.221/27, 192.168.1.193/27, and 192.168.1.222/27 are all valid host addresses in the same subnet and are reachable at Layer 2 without routing. That makes A, C, and D correct.

Option B is not correct because 192.168.1.192/27 is the network address of the subnet and cannot be assigned to a host by default. This question checks IP subnetting and the ability to identify valid hosts within the same broadcast domain.