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Question 281. What is the PRIMARY purpose of a CAPWAP tunnel between a Huawei Fit AP and a Wireless Access Controller (WAC)?

1. To replace all WLAN radio transmission
2. To operate only as a DHCP relay
3. To create an OSPF adjacency between wireless clients
4. To enable centralized AP management, configuration delivery, status maintenance, and, when configured, service-data transport

Correct Answer: 4. To enable centralized AP management, configuration delivery, status maintenance, and, when configured, service-data transport

Explanation:

CAPWAP is fundamental to Huawei’s centralized AC/WAC + Fit AP architecture. After an AP discovers and joins a controller, CAPWAP provides the logical control channel through which the controller monitors the AP, delivers configurations, and manages WLAN services. CAPWAP can also carry user service data when tunnel forwarding is selected. This allows many APs to be administered centrally rather than configured independently. In direct forwarding deployments, control traffic still uses the controller relationship even though ordinary service traffic can bypass the WAC.

Question 282. What must a Fit AP normally obtain before it can begin discovering and connecting to a WAC across an IP network?

1. A valid IP address
2. A BGP autonomous system number
3. An MPLS label
4. A VRRP virtual address

Correct Answer: 1. A valid IP address

Explanation:

An AP needs basic IP connectivity before it can establish a CAPWAP relationship with its controller. After starting, the AP normally obtains an IP address either through DHCP or through static configuration. It then begins the WAC discovery process by sending Discovery Request messages and evaluating responses from available controllers. Once a suitable WAC is selected, CAPWAP and associated security procedures can proceed. If the AP never obtains a valid management address or cannot route to the WAC, later onboarding steps cannot complete even if the wireless-radio configuration itself is correct.

Question 283. When a Huawei AP and WAC are separated by a Layer 3 IPv4 network, which DHCP option can provide the WAC IP address to the AP?

1. Option 3 only
2. Option 82 only
3. Option 43
4. Option 66 only

Correct Answer: 3. Option 43

Explanation:

When an AP and WAC are separated by Layer 3 routing, the AP may be unable to discover the controller using local broadcast discovery. Huawei supports supplying the WAC address through DHCP Option 43 for IPv4 AP onboarding. The DHCP server includes the WAC IP information in its response, after which the AP can send a unicast Discovery Request to the controller. This is useful in large campus environments where APs are deployed in many routed management subnets rather than sharing one Layer 2 segment with the WAC.

Question 284. What characterizes static WAC discovery on a Huawei Fit AP?

1. The AP discovers the WAC only through multicast routing
2. A list of WAC IP addresses is configured on the AP in advance
3. The WAC is learned only from LLDP
4. The AP must receive the WAC address from BGP

Correct Answer: 2. A list of WAC IP addresses is configured on the AP in advance

Explanation:

Huawei APs can discover WACs through static or dynamic methods. In static discovery, one or more WAC IP addresses are configured on the AP ahead of time. The AP can then directly send discovery traffic toward those known controller addresses after IP connectivity is established. Dynamic approaches can instead use mechanisms such as DHCP or DNS to locate the WAC. Static discovery provides predictable behavior and can be appropriate in controlled environments, while dynamic discovery often reduces manual configuration effort in large deployments containing many APs.

Question 285. What is the default AP authentication mode shown in Huawei’s CAPWAP deployment examples?

1. MAC address authentication
2. Anonymous authentication
3. Portal authentication
4. BGP MD5 authentication

Correct Answer: 1. MAC address authentication

Explanation:

Huawei WLAN deployment examples commonly show MAC address authentication as the default AP authentication mode. Under this model, the WAC recognizes and authenticates APs using their MAC-related identity as part of the onboarding process. Administrators can import AP information in advance and place APs into groups so that appropriate radio, regulatory, VAP, and other WLAN configuration can be delivered centrally. AP authentication is separate from end-user wireless authentication such as 802.1X or Portal authentication; it governs whether the infrastructure AP itself is permitted to join and be managed by the WAC.

Question 286. In WLAN tunnel forwarding mode, what happens to service traffic received by an AP from a wireless client?

1. It is always bridged directly onto the local wired VLAN
2. It is discarded unless the client runs BGP
3. It is converted into an STP BPDU
4. It is encapsulated in CAPWAP and sent to the WAC for centralized forwarding

Correct Answer: 4. It is encapsulated in CAPWAP and sent to the WAC for centralized forwarding

Explanation:

In tunnel forwarding, a Fit AP does not locally forward ordinary client service traffic directly into the wired network. Instead, it encapsulates the traffic into CAPWAP data packets and forwards those packets through the CAPWAP tunnel to the WAC. The controller decapsulates the traffic and performs the required Layer 2 or Layer 3 forwarding. This architecture centralizes service management and makes it easier to enforce consistent QoS and security policies. The tradeoff is increased WAC processing load and a potentially longer traffic path compared with direct forwarding.

Question 287. What is a PRIMARY advantage of direct forwarding compared with tunnel forwarding in a large WLAN?

1. It forces all user traffic through the WAC
2. It reduces WAC service-data processing load by allowing the AP to forward client traffic locally
3. It eliminates CAPWAP control communication
4. It removes the need for VLAN configuration

Correct Answer: 2. It reduces WAC service-data processing load by allowing the AP to forward client traffic locally

Explanation:

With direct forwarding, service traffic from wireless clients is forwarded from the AP into the local wired network according to configured VLAN and interface policies instead of being carried through the WAC. This can reduce controller load, shorten the data path, and improve forwarding efficiency, especially when many APs and users are present. The WAC still performs centralized control functions, and some control packets continue to traverse CAPWAP. Direct forwarding therefore changes the user-data path but does not convert the Fit AP into a completely independent Fat AP.

Question 288. In Huawei direct-forwarding WLAN mode, what happens to important control traffic such as 802.1X authentication packets?

1. It is always discarded by the AP
2. It bypasses both the AP and the WAC
3. It can still be sent to the WAC through the CAPWAP control relationship
4. It is converted to an MPLS packet

Correct Answer: 3. It can still be sent to the WAC through the CAPWAP control relationship

Explanation:

Direct forwarding refers primarily to how service data is handled. The AP forwards normal user traffic locally rather than tunneling all of it through the controller. Control functions, however, remain centralized. Huawei notes that packets involved in functions such as 802.1X authentication can still be sent toward the WAC through the CAPWAP relationship for processing. This distinction is important: direct forwarding improves data-plane efficiency, but the WAC continues to control AP operation, authentication workflows, and policy delivery. It does not eliminate the centralized management architecture.

Question 289. What characterizes Layer 2 Wi-Fi roaming?

1. The client must change from IPv4 to IPv6
2. The client must move between different WACs
3. The client always obtains a new subnet
4. The client roams while remaining within the same IP subnet

Correct Answer: 4. The client roams while remaining within the same IP subnet

Explanation:

Huawei classifies roaming as Layer 2 or Layer 3 based primarily on whether the client’s subnet changes. In Layer 2 roaming, the station moves between AP coverage areas but remains in the same IP subnet. This helps preserve service continuity because the client does not need to undergo the same network-layer change associated with movement into a different subnet. Huawei notes that roaming within the same VLAN pool is also treated as Layer 2 roaming. This model is commonly appropriate when neighboring APs serve users within the same logical network area.

Question 290. What characterizes Layer 3 Wi-Fi roaming?

1. The client must remain attached to the same AP
2. The client roams between different IP subnets
3. The client disables its wireless adapter during roaming
4. The client changes only its SSID name

Correct Answer: 2. The client roams between different IP subnets

Explanation:

In Layer 3 roaming, a wireless station moves between AP coverage areas associated with different IP subnets. The WLAN infrastructure must preserve service continuity while dealing with the fact that the user’s attachment point and Layer 3 network have changed. Huawei distinguishes this from Layer 2 roaming, where the user remains in the same subnet. During campus WLAN planning, Layer 3 roaming may be required when different physical areas or floors use separate service subnets but mobile users still need continuous application sessions as they move.

Question 291. What is intra-AC roaming?

1. A client roams between APs that are managed by the same WAC
2. A client roams between two separate autonomous systems
3. A client changes from WLAN to MPLS
4. An AP changes its management IP address

Correct Answer: 1. A client roams between APs that are managed by the same WAC

Explanation:

Huawei defines intra-AC roaming according to controller ownership. If a wireless station moves from one AP to another and both APs are managed by the same Wireless Access Controller, the event is intra-AC roaming. It can occur independently of whether the roam is classified as Layer 2 or Layer 3 from an IP-subnet perspective. Intra-AC roaming is generally easier to coordinate because one controller already has the required user and AP context. Huawei recommends this model for roaming within the same building in many medium- and large-campus designs.

Question 292. What is inter-AC roaming?

1. Roaming between two radios of the same AP only
2. Movement between different SSIDs without changing AP
3. A client roams between APs managed by different WACs
4. A client moves between two ports on the same switch

Correct Answer: 3. A client roams between APs managed by different WACs

Explanation:

Inter-AC roaming occurs when the station’s original AP and target AP are controlled by different WACs. The controllers need appropriate roaming-related connectivity and configuration so the user’s service can continue as the client moves between controller domains. Huawei distinguishes inter-AC roaming from intra-AC roaming, where the same WAC manages both APs. In medium- and large-campus planning, Huawei documentation notes that inter-AC roaming may be appropriate between buildings, while intra-AC roaming is frequently used within a building.

Question 293. What is the PRIMARY purpose of WLAN band steering?

1. To force all clients to use 2.4 GHz
2. To preferentially steer suitable dual-band clients toward 5 GHz to reduce 2.4 GHz congestion
3. To disable 5 GHz radios
4. To increase the number of 2.4 GHz overlapping channels

Correct Answer: 2. To preferentially steer suitable dual-band clients toward 5 GHz to reduce 2.4 GHz congestion

Explanation:

The 2.4 GHz band has fewer usable non-overlapping channels and is frequently more congested than 5 GHz. Many dual-band clients may nevertheless prefer 2.4 GHz when first associating. Huawei’s band steering feature encourages suitable dual-band stations to connect to 5 GHz instead. This can reduce 2.4 GHz load and interference and make better use of the additional channel resources available in the 5 GHz band. Band steering works best when radio coverage and service configuration are designed consistently across both frequency bands.

Question 294. Which condition is required for Huawei band steering to operate correctly across an AP’s 2.4 GHz and 5 GHz radios?

1. The radios must use different SSIDs and different authentication methods
2. Only the 2.4 GHz radio may broadcast an SSID
3. The AP must operate as a single-radio device
4. The two bands should provide the same SSID and security policy for the service

Correct Answer: 4. The two bands should provide the same SSID and security policy for the service

Explanation:

Band steering is intended to guide a dual-band client between equivalent wireless services on 2.4 GHz and 5 GHz. Huawei therefore requires the service to have the same SSID and security policy across the bands used for steering. Otherwise, the radios represent different WLAN services and cannot be treated as interchangeable association choices. Huawei also notes that single-radio devices do not support this function. Once correctly configured, band steering can prefer 5 GHz and help reduce load on the more congestion-prone 2.4 GHz band.

Question 295. Which 2.4 GHz channel set is commonly recommended to minimize adjacent-channel interference when 20 MHz channels are used?

1. 2, 4, and 8
2. 3, 7, and 10
3. 1, 6, and 11
4. 1, 2, and 3

Correct Answer: 3. 1, 6, and 11

Explanation:

In common 2.4 GHz WLAN deployments using 20 MHz channels, channels 1, 6, and 11 are widely used because they provide a non-overlapping channel plan in the regulatory environments where this scheme applies. Adjacent APs should preferably use different non-overlapping channels to reduce adjacent-channel interference. Huawei troubleshooting and radio-calibration guidance specifically recommends using a non-overlapping set such as 1, 6, and 11 where appropriate. Actual permitted channels still depend on the configured country code and local regulatory rules, so WLAN planning must follow regional requirements.

Question 296. What is the PRIMARY purpose of Huawei WLAN radio calibration?

1. To dynamically optimize parameters such as AP channels and transmit power based on the radio environment
2. To assign BGP Local Preference
3. To change wireless clients into Fit APs
4. To create MPLS tunnels between APs

Correct Answer: 1. To dynamically optimize parameters such as AP channels and transmit power based on the radio environment

Explanation:

Radio calibration is part of WLAN Radio Resource Management. It evaluates the surrounding wireless environment and adjusts parameters such as operating channels and transmit power so APs can work together more efficiently. Proper calibration helps reduce interference, fill coverage gaps, and avoid unnecessarily strong overlapping cells. Huawei provides automatic, manual, and scheduled calibration modes depending on the software and deployment. Automatic channel and transmit-power selection must be available for calibration to make these adjustments dynamically. The goal is improved RF performance, not routing-protocol or MPLS configuration.

Question 297. What must be enabled if radio calibration is expected to dynamically choose an AP’s operating channel?

1. Static BGP routing
2. VRRP preemption
3. Automatic channel selection
4. MPLS LDP

Correct Answer: 3. Automatic channel selection

Explanation:

Huawei documentation states that automatic channel selection must be enabled when the AP is expected to participate in radio calibration that changes channels dynamically. With automatic channel selection enabled, the AP can choose a suitable operating channel based on RF conditions. If it is disabled, the deployment uses fixed/manual channel behavior, so manually specified channels take effect instead. This distinction matters during troubleshooting because administrators sometimes configure a manual channel while automatic selection remains enabled and then find that the expected fixed value does not take effect.

Question 298. What is co-channel interference in a WLAN?

1. Interference caused when nearby APs use the same channel and their coverage areas overlap
2. An IP routing loop between WACs
3. An AP authentication failure
4. A mismatch in DHCP options

Correct Answer: 1. Interference caused when nearby APs use the same channel and their coverage areas overlap

Explanation:

Co-channel interference occurs when multiple radios operate on the same RF channel in overlapping coverage areas. The devices must contend for shared airtime, which can reduce throughput and increase delays or collisions as network density rises. Huawei specifically identifies co-channel interference as a common issue in dense campus deployments and provides RRM and interference-detection features to identify and mitigate it. Channel planning, automatic radio calibration, careful AP placement, and appropriate transmit-power settings can all reduce co-channel contention while still preserving sufficient WLAN coverage.

Question 299. A client cannot detect an AP’s SSID even though the radio is enabled and the channel is valid. Which radio condition could directly cause this problem?

1. A high BGP MED
2. An incorrect OSPF cost
3. A large MPLS label stack
4. AP transmit power that is too low for the client’s location

Correct Answer: 4. AP transmit power that is too low for the client’s location

Explanation:

If AP transmit power is too low, radio signals may become too weak for clients at the intended coverage location to discover or reliably associate with the WLAN. Huawei troubleshooting guidance specifically recommends checking radio transmit power when stations cannot detect the expected wireless signal. Increasing power may improve coverage, but maximum power is not always the ideal long-term solution because excessive transmit power can create additional overlap and interference with neighboring APs. WLAN design therefore balances sufficient coverage against interference, using radio calibration or carefully planned manual settings where appropriate.

Question 300. A large campus has hundreds of Fit APs. The organization wants centralized AP management, efficient local service forwarding, automatic controller discovery across routed IPv4 subnets, reduced 2.4 GHz congestion, seamless mobility, and automated RF optimization. Which design BEST meets these requirements?

1. Deploy independent Fat APs with manually fixed channels and no controller
2. Use a WAC with CAPWAP, DHCP Option 43 for AP discovery, direct forwarding where appropriate, band steering, planned roaming, and automatic radio calibration
3. Tunnel all traffic using GRE without WLAN control
4. Use only VLANs and static routes

Correct Answer: 2. Use a WAC with CAPWAP, DHCP Option 43 for AP discovery, direct forwarding where appropriate, band steering, planned roaming, and automatic radio calibration

Explanation:

The requirements align closely with Huawei’s centralized WLAN model. CAPWAP allows the WAC to centrally manage Fit APs and distribute configuration. DHCP Option 43 can provide WAC addresses to IPv4 APs across Layer 3 networks. Direct forwarding can reduce WAC data-plane load when centralized tunneling is unnecessary. Band steering makes better use of 5 GHz and reduces 2.4 GHz congestion. Proper Layer 2, Layer 3, intra-AC, or inter-AC roaming design supports mobile users, while automatic radio calibration can optimize channels and transmit power as RF conditions change.