H12-811_V2.0 Sample Questions Answers

This statement is true . ARP is a Layer 2 broadcast-based protocol used to resolve an IPv4 address into a MAC address within the same broadcast domain. If two PCs are connected to the same switch but cannot learn each other’s ARP entries, one likely reason is an incorrect VLAN configuration .

For example, if PC1 and PC2 are placed in different VLANs, or if one interface is configured with the wrong access VLAN, ARP broadcast frames from one PC will not reach the other PC because VLANs separate Layer 2 broadcast domains. As a result, the ARP request will not be received by the peer, and the MAC address cannot be resolved. Other causes may also exist, such as incorrect IP addressing, port isolation, or security policies, but VLAN misconfiguration is a very common and valid cause in campus switching scenarios. HCIA-Datacom teaches that ARP communication depends on correct Layer 2 domain membership, and VLAN planning or interface configuration errors often directly affect host-to-host communication even when both hosts are physically connected to the same switch.

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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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.

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On a non-root bridge, the root port is the port that receives the best BPDU toward the root bridge. STP selects the root port by comparing several parameters in order. The first important parameter is the root path cost (RPC) , so option B is correct. If multiple ports have the same RPC, the switch then compares the bridge ID (BID) of the upstream device sending the BPDU, making option C correct. If those are still equal, the switch compares the port ID (PID) of the upstream sending port, so option D is also correct.

If all of those values remain identical from the switch’s perspective, the device can finally compare the local port ID to determine which local interface becomes the root port, so option A is also correct. HCIA-Datacom teaches this comparison logic as part of STP election rules. The process ensures deterministic selection of a single root port on every non-root switch. Understanding the comparison sequence is essential for predicting STP topology behavior and for influencing port roles through path cost tuning or bridge-priority adjustments during campus network design and troubleshooting.

For two directly connected edge networks to communicate through intermediate routing, each end router must have a route to the remote destination network pointing to the correct next hop on the transit link. Since 10.0.0.0/24 is directly connected to R1 and 20.1.1.0/24 is directly connected to R3, R1 needs a route to 20.1.1.0/24, and R3 needs a route to 10.0.0.0/24.

Option A is correct because it configures on R1 a static route to the remote network 20.1.1.0/24 using next hop 10.0.0.2, which is the neighbor toward the transit path. Option D is correct because it configures on R3 a static route to the remote network 10.0.0.0/24 using next hop 20.1.1.1, which is the proper adjacent forwarding address in that direction. Option B is incorrect because a router cannot use a next hop that belongs to the remote destination network but is not directly reachable as a valid immediate forwarding address in this topology. Option C is also incorrect because the specified next hop is not the correct adjacent next-hop address for R3. HCIA-Datacom stresses that static routes must always point to a reachable next hop or outbound interface.

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In STP, the root bridge has all its active ports elected as designated ports on each connected segment. On non-root switches, one port is selected as the root port , and on each LAN segment, one designated port is elected based on the best BPDU. Since SW1 is the root bridge and all links have equal cost, the election depends first on the path cost to the root, then on bridge ID, and then on port ID if needed.

According to the topology, the ports that become designated are GE1/0/2 of SW2 , GE1/0/1 of SW2 , and GE1/0/3 of SW3 , which correspond to option A , B , and C . Option D is not a designated port in this topology because that segment has another port with a superior BPDU and therefore SW4’s port does not win the designated-port election. HCIA-Datacom emphasizes that designated ports are elected per segment , not per switch, and that every non-root switch must compare received BPDUs to determine root and designated roles. This question tests the ability to apply STP election logic rather than simply memorizing port-role definitions.

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This statement is true . When a device has multiple routes to the same destination prefix, route selection is based first on the longest prefix match , and when prefix length is the same, the device compares the route preference or administrative priority associated with each routing source. On Huawei devices, a direct route has a better preference than a static route , so the direct route is selected first when both routes have the same destination and mask.

A direct route is generated automatically when an IP address is configured on an interface and that interface is Up. Because the destination network is directly connected, this route is considered more trustworthy and efficient than a manually configured static route pointing to the same prefix. HCIA-Datacom uses this principle to explain route selection, routing-table generation, and troubleshooting cases where a configured static route does not appear as the active route because a direct or dynamic route has higher priority. This is a basic but important concept in IP forwarding and helps engineers correctly interpret routing tables on Huawei routers and Layer 3 switches.

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The correct answer is C. In the command output, the AP state is shown as ver-mismatch. This state directly indicates a version mismatch between the AP and the WAC. In Huawei WLAN deployment, a Fit AP must use a software version that is compatible with the WAC version. If the versions do not match, the AP may be discovered by the WAC and appear in the AP list, but it cannot successfully complete the online process.

Option A is incorrect because blacklist-related failures are displayed with blacklist-related status information, not ver-mismatch. Option B is also incorrect because authentication failures normally generate authentication-related fault indications. Option D is incorrect because configuration initialization failure would not be identified by the specific ver-mismatch state.

HCIA-Datacom troubleshooting knowledge emphasizes reading AP online states carefully. Common causes of AP online failure include IP address acquisition failure, CAPWAP tunnel establishment failure, insufficient licenses, authentication problems, and version mismatch. When the state explicitly shows ver-mismatch, the troubleshooting direction is clear: check AP and WAC software compatibility and upgrade or align the software version as needed.

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When multiple static routes exist to the same destination prefix and all next hops are reachable, the device selects the route with the highest priority , which on Huawei devices means the lowest preference value . In this question, all four static routes point to the same destination network 20.0.0.0/30, but they have different preference values.

The route through 10.1.1.2 uses the default static route preference , which is 60 on Huawei devices. The route through 10.1.2.2 has a preference of 70 , the route through 10.1.3.2 has a preference of 50 , and the route through 10.1.4.2 has a preference of 100 . Since 50 is the lowest value among them, the route via 10.1.3.2 is preferred and installed in the routing table. Therefore, option D is correct. HCIA-Datacom emphasizes that when prefix length is identical, route preference determines which route is active. This principle is widely used in route backup design, where primary and floating backup static routes are configured using different preference values to control failover behavior.

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This statement is false . In an Eth-Trunk operating in LACP mode , if the administrator sets the maximum number of active links to 3 and there is 1 standby link, then when one active member fails, LACP can automatically promote the standby member to active status. The purpose of the standby member is to maintain the configured active-link capacity whenever possible.

Therefore, after one active link fails, the normal expectation is not that the active-link count is reduced from 3 to 2 while the standby link remains idle. Instead, the standby link should participate and replace the failed member, so that the Eth-Trunk continues operating with 3 active links if the standby link and negotiation conditions are normal. This reflects the redundancy and fast recovery capabilities of LACP-based aggregation. HCIA-Datacom highlights that compared with manual mode, LACP provides more intelligent link selection, active/standby management, and fault adaptation. The statement is wrong because it ignores the intended behavior of the standby link in maintaining the number of active forwarding links after a failure.

Option D is correct. The AAA configuration binds the domain huawei.com to the authentication scheme auth1 , which uses RADIUS as the authentication mode, and to the accounting scheme acc1 , which also uses RADIUS. Therefore, when a user logs in with a user name in the format hcia-datacom@huawei.com , the device parses the suffix @huawei.com, matches the domain, and applies the configured RADIUS authentication method.

Option A is false because RADIUS does support accounting , and UDP port 1813 is commonly used for that purpose. Option B is false because a separate authorization server IP is not strictly required in this context; RADIUS can carry authorization attributes together with authentication/accounting processing depending on server behavior and device configuration. Option C is false because standard RADIUS communication uses UDP , not TCP, with authentication typically on port 1812 and accounting on 1813 . HCIA-Datacom teaches domain-based AAA processing as a key concept, where the user name suffix determines which authentication, authorization, and accounting policies are applied on the NAS device.

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.

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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.

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The protocol that cannot directly modify device configurations such as interface IP addresses or device names is SFTP , so option C is correct. SFTP is a secure file transfer protocol that runs over SSH and is mainly used to upload, download, and manage files between a client and a network device. It is commonly used for tasks such as transferring configuration files, system software, patches, or log files, but it does not itself provide an interactive or structured configuration modification mechanism.

By contrast, STelnet allows secure remote CLI login, through which an administrator can directly enter commands to change device settings. NETCONF is specifically designed for network configuration management and can modify configurations in a structured manner. SNMP can also modify certain managed object values through write operations when permissions and MIB support allow it, although in practice it is used more often for monitoring. HCIA-Datacom distinguishes between management-plane protocols based on their roles: interactive access, structured configuration, monitoring, and file transfer. This question checks whether the learner can identify SFTP as a file transfer tool rather than a direct configuration protocol.

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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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