View Full CWNP CWNA-109 Exam Dumps and Practice Test Dumps

 

Question 161.

Which RF term describes the ratio between the power delivered to an antenna and the power reflected back because of an impedance mismatch?

1. VSWR
   2. SNR
   3. RSSI
   4. EIRP

Correct Answer: 1. VSWR

Explanation:

Voltage Standing Wave Ratio, or VSWR, is associated with impedance matching in an RF transmission system. If the transmitter, feed line, connectors, and antenna are not properly matched, some energy can be reflected rather than efficiently radiated. A lower VSWR generally indicates a better impedance match, while a high VSWR can indicate a problem that may reduce efficiency or potentially stress RF components. SNR compares desired signal strength with noise, RSSI represents received signal strength, and EIRP describes effective radiated transmit power. CWNA candidates should understand that good RF design involves not only transmit power and antenna gain but also minimizing unnecessary losses and reflections in the RF system.

Question 162.

Which term describes the loss caused by connectors, cables, and other passive components between a transmitter and antenna?

1. Modulation gain
   2. System loss
   3. Spatial gain
   4. Coding gain only

Correct Answer: 2. System loss

Explanation:

System loss includes attenuation introduced by components such as coaxial cables, connectors, splitters, and adapters in the RF path. These losses reduce the power that actually reaches the antenna or receiver and therefore must be included in link-budget calculations. Longer cables and higher frequencies can increase attenuation depending on cable type and quality. Spatial gain and coding gain refer to different concepts, while modulation gain is not the appropriate description for passive cable loss. In installations using external antennas, WLAN professionals should carefully account for connector and cable losses because a high-gain antenna does not provide its full benefit if excessive loss occurs before RF energy reaches it.

Question 163.

Which calculation correctly represents a simplified EIRP value?

1. Receive sensitivity + SNR
   2. Noise floor + channel width
   3. Transmit power – cable loss + antenna gain
   4. RSSI – DHCP delay

Correct Answer: 3. Transmit power – cable loss + antenna gain

Explanation:

A simplified EIRP calculation begins with transmitter output power, subtracts losses in cables and connectors, and adds antenna gain. For example, a transmitter output of 20 dBm, 2 dB of cable loss, and 5 dBi of antenna gain produces approximately 23 dBm EIRP. Receive sensitivity, noise floor, and DHCP timing are not components of EIRP. Regulatory limits often apply to effective radiated power, so WLAN professionals must understand how antenna gain and system loss influence legal transmit configurations. This is particularly important when external directional antennas are used because their gain can significantly increase effective radiated power in the primary direction.

Question 164.

Which antenna pattern is generally most appropriate for covering a long warehouse aisle from one end?

1. Omnidirectional pattern only
   2. Isotropic radiator
   3. Ceiling antenna facing upward
   4. Directional antenna pattern**

Correct Answer: 4. Directional antenna pattern

Explanation:

A directional antenna can concentrate RF energy along a long warehouse aisle instead of radiating equally in all horizontal directions. This can improve coverage efficiency and reduce RF energy spilling into adjacent aisles or neighboring cells. The correct antenna depends on aisle width, shelving materials, mounting location, client height, and frequency band. Omnidirectional antennas may be suitable for open spaces but can create undesirable coverage behind metal racks in structured warehouse environments. Antenna selection should therefore be based on the desired radiation pattern rather than simply gain value. On-site validation remains important because metal shelving and inventory can substantially change propagation.

Question 165.

Which propagation behavior occurs when an RF wave bends around the edge of an obstacle?

1. Diffraction
   2. Reflection
   3. Refraction
   4. Absorption

Correct Answer: 1. Diffraction

Explanation:

Diffraction occurs when RF energy bends around the edge of an obstacle. This can allow some signal to reach areas that do not have perfect direct line of sight. Reflection occurs when energy bounces from a surface, refraction changes direction when moving between different media, and absorption converts some RF energy into another form such as heat. Diffraction is one reason wireless coverage does not end abruptly behind every obstruction. However, the resulting signal can still be weaker or altered. WLAN professionals should consider diffraction together with reflection, scattering, and absorption when evaluating real indoor and outdoor propagation.

Question 166.

Which RF propagation behavior is most likely when a signal encounters many small irregular objects and is redirected in multiple directions?

1. Channel bonding
   2. Scattering
   3. Authentication
   4. Polarization matching

Correct Answer: 2. Scattering

Explanation:

Scattering occurs when RF energy encounters irregular surfaces or objects that cause energy to be redirected in many directions. Examples can include rough surfaces, foliage, or collections of smaller objects. Reflection generally occurs from larger smoother surfaces, while diffraction bends energy around obstacles. Authentication and polarization matching are unrelated concepts. Scattering contributes to multipath because multiple versions of the same transmitted signal can reach a receiver through different paths. In modern MIMO systems, multipath can sometimes be beneficial, but severe or unpredictable scattering can also create challenging RF conditions and coverage variation.

Question 167.

Which measurement indicates the weakest signal level at which a receiver can successfully decode a specific modulation and coding scheme under defined conditions?

1. EIRP
   2. Antenna gain
   3. Receive sensitivity
   4. Channel utilization

Correct Answer: 3. Receive sensitivity

Explanation:

Receive sensitivity describes the minimum received signal level at which a radio can successfully decode a transmission under specified conditions. Sensitivity usually varies by PHY rate or modulation and coding scheme because higher data rates require better signal quality. A receiver may decode a robust low-rate transmission at a weaker signal level than a high-rate transmission. EIRP describes effective transmit power, antenna gain describes radiation concentration, and channel utilization represents how busy a channel is. Receive sensitivity is important in link-budget calculations and coverage planning because successful communication depends on both transmitted power and the receiver’s ability to detect and decode the resulting signal.

Question 168.

Which term describes the difference between the received signal level and the minimum receive sensitivity required for the intended data rate?

1. Noise floor
   2. Channel overlap
   3. Beacon overhead
   4. Fade margin**

Correct Answer: 4. Fade margin

Explanation:

Fade margin is the amount by which the received signal exceeds the minimum level needed for reliable operation. A healthy margin helps accommodate temporary changes caused by movement, environmental conditions, multipath fading, weather, foliage, or other variations. A link designed with virtually no margin may work under ideal conditions but become unstable when conditions change slightly. Noise floor, channel overlap, and beacon overhead describe different WLAN factors. Outdoor bridge designs commonly include a deliberate fade margin because long-distance RF links can be affected by changing environmental conditions over time.

Question 169.

Which statement best describes why transmit power should not automatically be set to maximum on every access point?

1. Excessive power can enlarge cells, increase contention, and create asymmetric links
   2. Maximum power disables WPA2
   3. Maximum power prevents DHCP
   4. Maximum power removes all roaming behavior

Correct Answer: 1. Excessive power can enlarge cells, increase contention, and create asymmetric links

Explanation:

Maximum transmit power may make an AP audible over a larger area than necessary. This can increase overlap with same-channel cells, enlarge contention domains, and encourage clients to remain associated with distant access points. It can also create an asymmetric link if client devices cannot transmit at comparable power. Good WLAN design balances AP transmit power with client capabilities, channel reuse, coverage targets, and application requirements. More transmit power is not automatically better. Security and DHCP are unrelated to power level, and roaming is not eliminated, although overly large cells can contribute to sticky-client behavior and delayed roaming.

Question 170.

Which feature allows an access point to advertise multiple logical WLANs on the same physical radio?

1. DFS
   2. Multiple BSSIDs/SSIDs
   3. MIMO only
   4. SIFS

Correct Answer: 2. Multiple BSSIDs/SSIDs

Explanation:

An access point can support multiple logical BSSs on the same physical radio, often presenting different SSIDs with corresponding BSSIDs. This allows administrators to provide separate logical WLAN services for different user groups or purposes. However, each additional BSS generates management overhead such as beaconing and probe responses, so excessive SSID counts can waste airtime. DFS manages radar-sensitive channels, MIMO concerns multiple antenna streams, and SIFS is an interframe spacing mechanism. WLAN design should keep SSID counts as low as practical while using policy and network segmentation to satisfy business requirements.

Question 171.

Which statement best describes the relationship between SSID and BSSID?

1. An SSID is a network name, while a BSSID identifies a specific BSS
   2. They are always identical hexadecimal values
   3. The BSSID is an IP subnet
   4. The SSID is the AP’s default gateway

Correct Answer: 1. An SSID is a network name, while a BSSID identifies a specific BSS

Explanation:

The SSID is the service set identifier that users commonly recognize as the WLAN name. A BSSID identifies a specific Basic Service Set and is typically based on a MAC address used by an AP radio. Multiple access points can advertise the same SSID as part of one Extended Service Set while each BSS still has a unique BSSID. The BSSID is not an IP subnet, and the SSID is not a gateway address. Understanding the distinction is essential when analyzing roaming because a client may move between different BSSIDs while remaining connected to the same SSID.

Question 172.

Which condition is most likely to increase probe and beacon overhead on a channel?

1. Lower Ethernet switch utilization
   2. Fewer client devices
   3. Higher AP mounting height only
   4. Advertising many SSIDs**

Correct Answer: 4. Advertising many SSIDs

Explanation:

Each configured BSS generally generates periodic beacon traffic and can respond to applicable probe requests. Therefore, advertising many SSIDs can significantly increase management-frame overhead, especially if low basic rates are configured. This consumes airtime that could otherwise be used for client data. Switch utilization and AP mounting height do not directly create additional beacon streams. Enterprise WLANs often reduce SSID counts and use identity-based policies, VLAN assignment, or role-based access to provide segmentation without multiplying the number of advertised networks. Airtime should be treated as a limited resource.

Question 173.

Which security mode commonly uses a single shared passphrase rather than individual 802.1X credentials?

1. Personal mode using a pre-shared key
   2. Enterprise 802.1X only
   3. Open System with no key
   4. RADIUS accounting only

Correct Answer: 1. Personal mode using a pre-shared key

Explanation:

Personal Wi-Fi security modes commonly use a pre-shared key or passphrase that is shared among authorized devices. This can be appropriate for homes or some smaller and specialized environments. Enterprise authentication instead commonly uses 802.1X/EAP with individualized user or device credentials and centralized authentication services. Open networks provide no comparable shared secret, while RADIUS accounting alone does not define Wi-Fi access authentication. Shared passphrases are easier to deploy but can be harder to revoke for one user, and widespread knowledge of the same credential can create management and accountability challenges.

Question 174.

Which security practice best reduces the risk of users unknowingly submitting credentials to an unauthorized enterprise authentication server?

1. Disable certificate validation
   2. Configure clients to validate the trusted server certificate and CA
   3. Use one password for all employees
   4. Hide the SSID

Correct Answer: 2. Configure clients to validate the trusted server certificate and CA

Explanation:

Client-side validation of the authentication server’s certificate is critical in many EAP deployments. The client should verify that the certificate chains to an approved certificate authority and that the server identity matches expected values. If users accept arbitrary certificates, an attacker may be able to operate a rogue authentication server and attempt to collect credentials. Hiding the SSID does not provide meaningful protection, and using a shared password reduces accountability. Proper certificate validation should be centrally configured where possible so users are not expected to make security decisions during connection attempts.

Question 175.

Which type of rogue device presents the greatest security concern when it imitates an organization’s legitimate WLAN to attract clients?

1. Ethernet hub
   2. Spectrum analyzer
   3. Evil twin access point
   4. Passive antenna

Correct Answer: 3. Evil twin access point

Explanation:

An evil twin is an unauthorized access point configured to imitate a legitimate WLAN, often by advertising the same or a similar SSID. Its goal may be to trick users into connecting so traffic or credentials can be intercepted. Strong enterprise authentication, certificate validation, user education, and wireless monitoring can reduce this risk. A spectrum analyzer and passive antenna are diagnostic or RF components rather than malicious WLAN impersonation devices. Because SSIDs are not secret and can be easily copied, security should rely on cryptographic authentication and validation rather than assuming the network name proves legitimacy.

Question 176.

Which security technology should be avoided because its cryptographic design is fundamentally weak and obsolete?

1. WPA3
   2. WPA2 with AES-based protection
   3. 802.1X/EAP
   4. WEP**

Correct Answer: 4. WEP

Explanation:

Wired Equivalent Privacy, or WEP, is obsolete and has fundamental cryptographic weaknesses that make it unsuitable for securing modern WLANs. Its design allows keys and traffic to be compromised using well-known techniques. WPA and especially WPA2 were introduced to address major WEP deficiencies, while newer WPA3 security provides additional improvements. 802.1X/EAP supports enterprise authentication and is not inherently a weak legacy security mechanism. WLAN professionals should remove WEP wherever possible rather than preserving it for legacy compatibility, because supporting obsolete security can undermine the protection of the entire wireless environment.

Question 177.

Which WLAN troubleshooting symptom most strongly suggests a possible Layer 2 or 802.11 issue rather than a DHCP problem?

1. The client never completes association with the access point
   2. The client associates successfully but receives no IP address
   3. The client has an IP address but DNS fails
   4. The client can ping locally but not access one web application

Correct Answer: 1. The client never completes association with the access point

Explanation:

If a client never successfully associates with an access point, the failure is occurring before DHCP normally becomes relevant. Troubleshooting should therefore focus first on WLAN discovery, authentication, association, security capabilities, signal conditions, and management-frame exchanges. If association succeeds but no IP address is obtained, DHCP becomes a more likely area of investigation. DNS issues occur later after IP connectivity exists, and application-specific failures may be even higher in the protocol stack. A layered troubleshooting approach prevents administrators from wasting time investigating services that are not yet involved in the connection process.

Question 178.

Which troubleshooting tool is best suited to identifying excessive retransmissions and analyzing 802.11 reason or status codes?

1. Spectrum analyzer only
   2. Wireless protocol analyzer
   3. Cable toner
   4. DNS server log only

Correct Answer: 2. Wireless protocol analyzer

Explanation:

A wireless protocol analyzer captures and decodes 802.11 frames, making it useful for identifying retransmissions, retry behavior, management-frame status codes, reason codes, authentication sequences, and roaming exchanges. A spectrum analyzer provides physical-layer visibility into RF energy and is especially useful for non-Wi-Fi interference, but it does not decode protocol fields. Cable tools and DNS logs operate outside the wireless MAC layer. Troubleshooting complex WLAN issues often requires both spectrum and protocol analysis, because one explains RF conditions while the other reveals how 802.11 devices are behaving in response.

Question 179.

Which survey activity provides the strongest evidence that a WLAN supports the actual devices used by employees?

1. Validation testing with representative client devices
   2. Testing only with the survey laptop
   3. Reviewing only AP specifications
   4. Using only predictive modeling

Correct Answer: 1. Validation testing with representative client devices

Explanation:

Representative client testing is important because client radios vary in transmit power, receive sensitivity, antenna design, supported bands, spatial streams, roaming behavior, and security capabilities. A survey laptop may have a better radio than the devices employees actually use and could therefore produce overly optimistic results. AP specifications alone do not describe client behavior, while predictive modeling cannot reproduce every real-world device characteristic. Validation should include important device classes such as laptops, phones, scanners, tablets, or voice handsets when those endpoints are critical to business operations.

Question 180.

A WLAN performs well overnight but becomes slow every workday when a large number of users arrive. Which area should be investigated first?

1. Whether the AP mounting brackets are the correct color
   2. Whether DNS domain names are long
   3. Whether every AP has the same model number
   4. Capacity, airtime utilization, contention, client density, retries, and channel reuse**

Correct Answer: 4. Capacity, airtime utilization, contention, client density, retries, and channel reuse

Explanation:

A problem that appears primarily when many users are active strongly suggests a capacity or airtime issue rather than a basic coverage failure. The investigation should examine channel utilization, active client counts, application demand, retry rates, PHY rates, channel width, co-channel contention, and neighboring cell reuse. The WLAN may have excellent coverage but insufficient available airtime during peak periods. Cosmetic hardware details and naming conventions are irrelevant. Capacity problems should be addressed through evidence-based design changes such as improving channel reuse, reducing unnecessary overhead, adjusting cell sizes, balancing bands, or adding carefully planned capacity where justified.