View Full Huawei H12-811 V2.0 Exam Dumps and Practice Test Dumps

 

Question 341.

Which protocol is primarily used to resolve an IPv4 address into a MAC address on the local Ethernet network?

1. DNS
   2. ARP
   3. DHCP
   4. OSPF

Correct Answer: 2. ARP

Explanation:

ARP, or Address Resolution Protocol, enables an IPv4 device to determine the MAC address associated with another IPv4 address on the same local Layer 2 network. When a host needs to communicate with a local destination and does not already know the destination MAC address, it broadcasts an ARP request. The device that owns the requested IPv4 address responds with an ARP reply containing its MAC address. The sender can then store the mapping temporarily in its ARP table and use it to construct Ethernet frames. If the destination is on a remote subnet, the sender normally resolves the MAC address of its default gateway instead of the remote host. DNS resolves names, DHCP assigns addresses, and OSPF exchanges routing information.

Question 342.

Which Huawei VRP command is most appropriate for viewing dynamically learned IPv4-to-MAC address mappings?

1. display vlan
   2. display mac-address
   3. display ip routing-table
   4. display arp

Correct Answer: 4. display arp

Explanation:

The display arp command shows ARP table entries on a Huawei VRP device. These entries map IPv4 addresses to Layer 2 MAC addresses for devices located on directly reachable Ethernet networks. This command is valuable when a route exists but communication with a local host or next-hop router still fails. If an expected ARP entry is missing, administrators should investigate interface status, VLAN membership, IP addressing, physical connectivity, and whether the neighboring device is operational. display mac-address shows the switch’s Layer 2 forwarding database rather than IP-to-MAC resolution information. display ip routing-table shows Layer 3 routes, while display vlan provides VLAN-related information. ARP inspection therefore helps bridge the troubleshooting gap between routing decisions and actual Ethernet frame delivery.

Question 343.

Which address does an Ethernet switch primarily examine when learning where devices are connected?

1. Source MAC address
   2. Destination IP address
   3. Default gateway address
   4. DNS server address

Correct Answer: 1. Source MAC address

Explanation:

An Ethernet switch learns device locations by examining the source MAC address of frames arriving on its ports. The switch associates the source MAC address with the incoming interface and the relevant VLAN in its MAC address table. When later frames are sent toward that MAC address, the switch can forward them through the correct port rather than flooding them. Destination MAC addresses are used when making forwarding decisions, but the learning process is based on source addresses. Destination IP addresses are mainly relevant to routers operating at Layer 3. Default gateway and DNS server addresses do not determine normal Layer 2 learning. Dynamic MAC learning allows switched Ethernet networks to operate efficiently without administrators manually configuring the location of every endpoint.

Question 344.

What does a switch normally do with an Ethernet frame whose destination MAC address is unknown?

1. Sends it only to the router
   2. Drops it immediately
   3. Floods it within the relevant VLAN
   4. Converts it to an ARP reply

Correct Answer: 3. Floods it within the relevant VLAN

Explanation:

When a switch receives a unicast Ethernet frame for a destination MAC address that is not present in its MAC address table, it normally floods that frame through appropriate ports belonging to the same VLAN, except the port on which the frame arrived. This behavior is called unknown-unicast flooding. If the destination device responds, the switch learns its source MAC address and can subsequently forward traffic directly through the correct interface. Flooding remains restricted by VLAN boundaries, so the frame is not automatically sent into unrelated VLANs. The switch does not automatically forward unknown traffic only to a router, nor does it transform arbitrary Ethernet frames into ARP traffic. Understanding this behavior is useful when troubleshooting high flooding levels, missing MAC entries, or unstable Layer 2 forwarding.

Question 345.

Which Huawei VRP command displays the switch’s MAC address forwarding table?

1. display mac-address
   2. display arp
   3. display interface brief
   4. display ospf peer

Correct Answer: 1. display mac-address

Explanation:

The display mac-address command displays MAC address entries learned or configured on a Huawei switch. The output can help identify which port and VLAN are associated with a particular endpoint. This makes it useful for locating devices, verifying correct Layer 2 forwarding, and troubleshooting unexpected traffic paths. For example, if an endpoint should be connected to one access port but its MAC address appears on a trunk interface, the administrator may need to investigate the physical topology or downstream switching structure. display arp maps IPv4 addresses to MAC addresses, while display ospf peer provides routing-neighbor information. Layer 2 troubleshooting commonly involves checking interface state, VLAN configuration, and the MAC table together.

Question 346.

Which IEEE standard defines VLAN tagging on Ethernet trunk links?

1. IEEE 802.11
   2. IEEE 802.1Q
   3. IEEE 802.1X
   4. IEEE 802.3af

Correct Answer: 2. IEEE 802.1Q

Explanation:

IEEE 802.1Q defines the VLAN tagging mechanism used to identify VLAN membership when Ethernet frames traverse trunk links. A VLAN tag is inserted into the frame and contains information including a VLAN identifier. This allows one physical trunk to carry traffic for multiple logical VLANs while maintaining separation between their Layer 2 broadcast domains. Access ports usually connect to endpoints and normally transmit untagged frames, while trunk ports commonly use 802.1Q tagging between VLAN-aware devices. IEEE 802.11 defines wireless LAN technologies, IEEE 802.1X relates to port-based access control, and IEEE 802.3af is associated with Power over Ethernet. Correct VLAN tagging and allowed-VLAN configuration are fundamental to multi-switch VLAN connectivity.

Question 347.

Which Huawei VRP command changes an Ethernet interface to trunk mode?

1. trunk enable
   2. switchport mode trunk
   3. port link-type trunk
   4. vlan trunk mode

Correct Answer: 3. port link-type trunk

Explanation:

The port link-type trunk command configures a Huawei Ethernet interface to operate as a trunk. A trunk can transport traffic belonging to multiple VLANs between switches, routers, firewalls, servers, or other VLAN-aware devices. After enabling trunk mode, the administrator must normally specify which VLANs are allowed to pass through the interface. On Huawei VRP, this is commonly accomplished with port trunk allow-pass vlan. A physical trunk can remain operational even if required VLANs are missing from its permitted list, which can create a situation where some VLANs work and others do not. Recognizing Huawei-specific VRP syntax is important because switchport mode trunk is associated with other vendors and is not the standard Huawei command.

Question 348.

Which Huawei VRP command permits VLANs 10, 30, and 50 on a trunk interface?

1. trunk allowed 10 30 50
   2. switchport trunk allow 10 30 50
   3. vlan trunk permit 10 30 50
   4. port trunk allow-pass vlan 10 30 50**

Correct Answer: 4. port trunk allow-pass vlan 10 30 50

Explanation:

The port trunk allow-pass vlan 10 30 50 command permits traffic for VLANs 10, 30, and 50 to traverse a Huawei trunk interface. Trunk configuration must be consistent with the intended network topology, and the required VLANs should exist on relevant switches. If VLAN 30 is configured correctly on access ports but omitted from an intermediate trunk’s allow-pass list, hosts in VLAN 30 may communicate locally on one switch but fail to reach devices across the trunk. This is a common Layer 2 troubleshooting scenario. Administrators should inspect the link type, permitted VLANs, VLAN existence, and port status at both ends of each trunk. Properly configured trunks enable VLANs to extend across multiple switches without merging their separate broadcast domains.

Question 349.

Which protocol elects a root bridge in order to prevent Layer 2 switching loops?

1. STP
   2. VRRP
   3. OSPF
   4. LACP

Correct Answer: 1. STP

Explanation:

Spanning Tree Protocol, or STP, prevents Layer 2 loops in switched Ethernet networks by creating a loop-free logical topology. The protocol elects one switch as the root bridge and calculates preferred paths relative to that device. Redundant paths that are not required for normal forwarding can be placed into non-forwarding states. This is necessary because Ethernet frames lack a routing-style hop limit, so a Layer 2 loop can cause broadcasts and unknown-unicast frames to circulate repeatedly. Such loops can create broadcast storms, duplicate frames, and unstable MAC address tables. VRRP provides first-hop gateway redundancy, OSPF is a Layer 3 routing protocol, and LACP manages link aggregation. These technologies may coexist with STP but solve different network problems.

Question 350.

Which switch wins the STP root bridge election?

1. The switch with the highest IP address
   2. The switch with the lowest bridge ID
   3. The switch with the most interfaces
   4. The switch with the highest VLAN ID

Correct Answer: 2. The switch with the lowest bridge ID

Explanation:

STP elects the switch with the lowest bridge ID as the root bridge. The bridge ID includes a configurable priority value together with MAC-address-related information. Administrators can influence root election by configuring a lower priority on the switch that should become the preferred root. If priorities are equal, the MAC-address-related portion of the bridge ID acts as a tie-breaker. Deliberate root placement is important because all other switches calculate their Layer 2 paths relative to the root. In a hierarchical network, a distribution or aggregation switch is often selected rather than allowing an access-layer switch to become root accidentally. IP addresses, VLAN IDs, and interface counts do not directly determine the STP root election.

Question 351.

Which STP port on a non-root switch represents its best path toward the root bridge?

1. Root port
   2. Designated port
   3. Alternate port only
   4. Edge port

Correct Answer: 1. Root port

Explanation:

A non-root switch selects one root port that provides its best path toward the STP root bridge. The decision is based primarily on the accumulated root path cost, with additional tie-breakers applied if necessary. Normal traffic heading toward the root bridge leaves through this port. The root bridge itself does not have a root port because it is the reference point for the topology. Designated ports are selected for individual Ethernet segments, while alternate or blocked paths provide redundancy without creating loops. Understanding root-port selection allows administrators to predict traffic flow and determine which redundant links are expected to remain inactive during normal operation. Unexpected root-port selection may indicate incorrect root bridge placement or unusual STP path costs.

Question 352.

Which spanning-tree protocol converges more quickly than traditional STP and is associated with IEEE 802.1w?

1. OSPF
   2. MSTP only
   3. VRRP
   4. RSTP**

Correct Answer: 4. RSTP

Explanation:

Rapid Spanning Tree Protocol, or RSTP, improves Layer 2 convergence compared with traditional STP and is associated with IEEE 802.1w. It maintains the objective of preventing loops but introduces faster transitions and additional port roles that allow the network to react more quickly when links fail or topology changes occur. Traditional STP may require longer transition periods before a redundant link begins forwarding, whereas RSTP can use rapid negotiation under suitable conditions. Faster convergence is valuable for voice, video, and other applications that are sensitive to interruptions. OSPF is a Layer 3 routing protocol, VRRP protects default gateways, and MSTP extends spanning-tree behavior to support multiple spanning-tree instances.

Question 353.

Which protocol uses a link-state database and SPF calculation to determine Layer 3 routes?

1. OSPF
   2. RIP
   3. ARP
   4. STP

Correct Answer: 1. OSPF

Explanation:

OSPF is a link-state Interior Gateway Protocol that builds a database describing the network topology and uses the Shortest Path First algorithm to calculate preferred routes. Routers exchange Link State Advertisements and attempt to maintain synchronized link-state information within an area. OSPF uses cost as its primary metric and supports hierarchical design through areas, with Area 0 serving as the backbone. This design scales better than simple distance-vector routing in many enterprise environments. RIP instead relies mainly on hop count, ARP performs local IPv4 address resolution, and STP is a Layer 2 loop-prevention protocol. OSPF troubleshooting commonly involves examining neighbor relationships, area settings, interface state, routing information, and link-state data.

Question 354.

Which Huawei VRP command is most appropriate for examining OSPF neighbors?

1. display ospf routing
   2. display ospf peer
   3. display ip interface brief
   4. display vlan

Correct Answer: 2. display ospf peer

Explanation:

The display ospf peer command provides information about OSPF neighbors and adjacency states on Huawei VRP devices. If expected OSPF routes are missing, confirming that the required neighbor relationship has formed is an important troubleshooting step. The command can show peer Router IDs, addresses, states, and other protocol information. If a neighbor does not reach the expected state, administrators should examine interface addressing, OSPF area configuration, Hello and Dead timers, authentication settings, network type, and physical connectivity. display ospf routing focuses on OSPF-calculated routes rather than neighbor relationships, while interface and VLAN commands provide lower-layer information. Successful routing requires both a functioning underlying network and correctly formed routing-protocol adjacencies.

Question 355.

Which OSPF state normally indicates that two routers have completed database synchronization and formed a full adjacency?

1. Init
   2. 2-Way
   3. Full
   4. ExStart

Correct Answer: 3. Full

Explanation:

The OSPF Full state indicates that neighboring routers have completed the necessary link-state database synchronization and established a full adjacency. Before reaching Full, routers may progress through states such as Init, 2-Way, ExStart, Exchange, and Loading. If an adjacency remains in one of these intermediate states, the administrator should investigate the relevant OSPF parameters and underlying connectivity. On broadcast multiaccess networks, not every pair of routers necessarily forms a full adjacency because DR and BDR behavior influences adjacency formation. However, where a full relationship is expected, the Full state represents normal successful completion. Examining neighbor state is therefore one of the most effective ways to determine whether OSPF route exchange can occur correctly.

Question 356.

Which OSPF router type connects one OSPF area to another?

1. Designated Router only
   2. Backup Designated Router only
   3. Internal router
   4. Area Border Router**

Correct Answer: 4. Area Border Router

Explanation:

An Area Border Router, or ABR, connects multiple OSPF areas. In a conventional hierarchical design, an ABR participates in Area 0 and at least one additional area. It maintains area-specific link-state information and exchanges inter-area routing information. Internal routers have all OSPF-enabled interfaces within the same area, while DR and BDR roles apply to certain multiaccess network segments and do not define inter-area connectivity. ABRs help OSPF scale because detailed topology information can remain largely contained within individual areas. When inter-area connectivity fails, administrators should verify that the expected ABR interfaces are assigned to the correct areas and that Area 0 connectivity is functioning properly.

Question 357.

Which protocol allows multiple private IPv4 hosts to share one public address through translation of transport-layer ports?

1. NAPT
   2. Static NAT only
   3. OSPF
   4. DHCP relay

Correct Answer: 1. NAPT

Explanation:

Network Address and Port Translation, or NAPT, allows many private IPv4 hosts to communicate through one or a small number of public IPv4 addresses. The translation device modifies both IP address and transport-layer port information so that separate sessions can be distinguished. For example, several internal hosts can simultaneously establish web connections through the same public address because each translated session uses unique port information. The NAT device maintains translation state so returning traffic is delivered to the correct private host. Static NAT provides fixed one-to-one address mappings and does not provide the same level of address sharing. OSPF exchanges routes, while DHCP relay forwards DHCP traffic between subnets. NAPT is widely used because it significantly reduces public IPv4 address consumption.

Question 358.

Which Huawei routing concept generally prefers the route with the lower preference value when identical destination prefixes are learned from different sources?

1. VLAN priority
   2. Route preference
   3. MAC aging
   4. STP path cost only

Correct Answer: 2. Route preference

Explanation:

Huawei VRP uses route preference to help choose among routes to the same destination prefix learned from different routing sources. In general, a lower preference value indicates a more preferred route. This concept allows the router to decide between candidates such as direct, static, OSPF, or other protocol routes. Longest-prefix matching is considered first when route prefix lengths differ. Preference becomes especially relevant when the destination network and mask are identical. After route-source preference is considered, protocol-specific metrics may further distinguish suitable candidates. Administrators should avoid confusing route preference with OSPF cost or STP path cost, because those values operate within their own protocol-selection processes. Understanding Huawei route preference is important when multiple routing methods coexist.

Question 359.

Which Huawei VRP command can be used to verify which route the router has selected toward an IPv4 destination?

1. display mac-address
   2. display vlan
   3. display ip routing-table
   4. display lldp neighbor brief

Correct Answer: 3. display ip routing-table

Explanation:

The display ip routing-table command shows the IPv4 routing table used by a Huawei VRP device. It allows administrators to determine whether a route exists toward a destination, which routing source supplied it, what its next hop is, and which outbound interface is selected. This is one of the most important commands in Layer 3 troubleshooting. If several routes have been learned, the routing table helps show which route has actually become active according to longest-prefix matching, route preference, and protocol metrics. If the expected route is missing, administrators can then inspect static configuration or routing-protocol behavior. MAC, VLAN, and LLDP commands provide information at different layers and do not show the selected IP forwarding path.

Question 360.

A Huawei router can reach a remote server by IP address, but users cannot reach the same server using its hostname. Which service should be investigated first?

1. STP
   2. LACP
   3. VRRP
   4. DNS**

Correct Answer: 4. DNS

Explanation:

If communication succeeds when the server’s IP address is used but fails when users enter its hostname, the underlying IP route is probably functioning and the problem is most likely related to name resolution. DNS should therefore be investigated first. Administrators should verify that the client or router has the correct DNS server configuration, confirm reachability to that DNS server, and test whether the required hostname record exists and resolves to the expected address. A record may also be outdated or incorrect even if the DNS server itself is reachable. STP prevents Layer 2 loops, LACP manages link aggregation, and VRRP provides redundant default gateways. None of those protocols translates hostnames into IP addresses, making DNS the relevant service for this symptom.