CWNP CWAP-404 Exam Practice Test Instant Access

Question 1

802.11k Neighbor Requests and Neighbor Reports are sent in what type of Management Frames?

ARRM

BAction

CBeacon

DReassociation Request and Reassociation Response

Answer : B

802.11k Neighbor Requests and Neighbor Reports are sent in Action frames. An Action frame is a Management frame that is used to perform various operations or functions related to the operation or maintenance of a wireless network. An Action frame consists of a Category field that indicates the type of action being performed, and a variable-length Action Details field that contains specific information related to the action. For example, an Action frame with a Category field value of 5 indicates a Radio Measurement action, and the Action Details field may contain a Neighbor Request or a Neighbor Report subelement . Reference: CWAP-404 Certified Wireless Analysis Professional Study and Reference Guide, Chapter 6: MAC Sublayer Frame Exchanges, page 207; CWAP-404 Certified Wireless Analysis Professional Study and Reference Guide, Chapter 6: MAC Sublayer Frame Exchanges, page 208; CWAP-404 Certified Wireless Analysis Professional Study and Reference Guide, Chapter 12: 802.11k/v/r/u/w/ai Amendments, page 434.

Question 2

A PHY Header is added to the PSDU at which layer?

ALLC

BNetwork

CPHY

DMAC

Answer : C

A PHY header is added to the PSDU at the PHY layer. A PHY header is a part of the PPDU that contains information such as modulation, coding, and data rate. The PHY header is added by the PHY layer when it converts a PSDU to a PPDU for transmission, or removed by the PHY layer when it converts a PPDU to a PSDU for reception. The other layers do not add or remove a PHY header.Reference:[Wireless Analysis Professional Study Guide CWAP-404], Chapter 4: 802.11 Physical Layer, page 97-98

Question 3

A manufacturing facility has installed a new automation system which incorporates an 802.11 wireless network. The automation system is controlled from tablet computers connected via the WLAN. However, the automation system has not gone live due to problem with the tablets connecting to the WLAN. The WLAN vendor has been onsite to perform a survey and confirmed good primary and secondary coverage across the facility. As a CWAP you are called in to perform Spectrum Analysis to identify any interference sources. From the spectrum analysis, you did not identify any interference sources but were able to correctly identify the issue. Which of the following issues did you identify from the spectrum analysis?

AThe tablets are connecting to the wrong SSID

BThe tablets are entering power save mode and failing to wake up to receive the access points transmissions

CA high noise floor has resulted in a SNR of less than 20dB

DThere is a power mismatch between the APs and the clients

Answer : D

The most likely issue that can be identified from the spectrum analysis is a power mismatch between the APs and the clients. A power mismatch occurs when the APs transmit at a higher power level than the clients, or vice versa. This can cause asymmetric communication, where one side can hear the other, but not vice versa. This can result in poor performance, disconnections, or packet loss. A spectrum analysis can reveal a power mismatch by showing different signal amplitudes or RSSI values for the APs and the clients on the same channel or frequency. The other options are not correct, as they cannot be identified from the spectrum analysis alone. The tablets' SSID, power save mode, and noise floor can be determined by using other tools or methods, such as protocol analysis, site survey, or device configuration.Reference:[Wireless Analysis Professional Study Guide CWAP-404], Chapter 3: Spectrum Analysis, page 79-80

Question 4

Which common feature of a Spectrum Analyzer would be the best to help you locate a non-802.11 interference source?

AMax hold

BMin hold

CLocation filter

DDevice finder

Answer : D

The device finder is a common feature of a spectrum analyzer that helps locate a non-802.11 interference source. The device finder uses a directional antenna to measure the signal strength of a specific frequency or signal source. By pointing the antenna in different directions, the device finder can indicate the direction and distance of the interference source. The device finder can also filter out other signals that are not related to the interference source. The other options are not correct, as they do not help locate a non-802.11 interference source. Max hold and min hold are features that show the maximum and minimum RF power levels over time, respectively. Location filter is a feature that filters out signals that are not from a specific location or area.Reference:[Wireless Analysis Professional Study Guide CWAP-404], Chapter 3: Spectrum Analysis, page 77-78

Question 5

You have installed a new 802.1 lac WLAN configured with 80 MHz channels. Users in one area are complaining about poor performance. This area is currently served by a single AP. You take a spectrum analysis capture in the poor performing are

a. While examining the waterfall plot you notice the airtime utilization is higher on the first 20 MHz of the 80 MHz channel when compared to the rest of the channel. What do you conclude?

AThe AP is misconfigured and needs to be reconfigured to 80 MHz operation

BNon-Wi-Fi interference is preventing the APs 80 MHz operation

CThe first 20 MHz is the AP's primary channel and higher airtime utilization on the primary channel is normal when an AP is configured for 80 MHz operation

DRRM is enabled and has dynamically picked a 20 MHz channel

Answer : B

The most likely cause of higher airtime utilization on the first 20 MHz of the 80 MHz channel is non-Wi-Fi interference. Non-Wi-Fi interference can prevent an AP from using its full channel width, as it will degrade the signal quality and increase the noise floor on some parts of the channel. This will force the AP to fall back to a narrower channel width, such as 20 MHz or 40 MHz, to maintain communication with its clients. The waterfall plot can help identify non-Wi-Fi interference by showing spikes or bursts of RF energy on specific frequencies or sub-channels. The other options are not correct, as they do not explain why only the first 20 MHz of the channel has higher airtime utilization.Reference:[Wireless Analysis Professional Study Guide], Chapter 3: Spectrum Analysis, page 74-75

Question 6

You're the WLAN administrator for a large retailer based at the HQ in New York. The London-based office has been complaining about WLAN disconnections around lunch time each day. You suspect this might be interference from the staff microwave, how might you test your theory from the New York office?

AAsk a local member of staff to change the frequency of the microwave and see if the disconnections stop

BAsk a local member of staff to take some pictures of the microwave, including some close-ups of the door seal so that you can assess it

CAccess the microwave remotely and run a diagnostic check

DPlace one of the London APs into spectrum analyzer mode and monitor the situation over lunch time

Answer : D

The best way to test the theory of microwave interference from the New York office is to use a remote spectrum analyzer. By placing one of the London APs into spectrum analyzer mode, you can capture and analyze the RF spectrum in the London office over lunch time. You can then look for any signs of microwave interference, such as high duty cycle, high amplitude, or frequency hopping on the 2.4 GHz band. This method does not require any physical access to the microwave or any changes to its frequency.Reference:[Wireless Analysis Professional Study Guide], Chapter 3: Spectrum Analysis, page 64

Question 7

Which one of the following is required for Wi-Fi integration in laptop-based Spectrum Analyzer software in addition to the spectrum analysis adapter?

AAn 802.11 wireless adaptor

BA firmware upgrade for the spectrum analysis adapter

CA directional antenna

DSNMP read credentials to the WLAN controller or APs

Answer : A

An 802.11 wireless adaptor is required for Wi-Fi integration in laptop-based spectrum analyzer software in addition to the spectrum analysis adapter. The spectrum analysis adapter is a hardware device that captures the RF signals in the wireless environment and sends them to the spectrum analyzer software for analysis and display. The 802.11 wireless adapter is a hardware device that connects the laptop to the wireless network and allows the spectrum analyzer software to correlate the RF data with the Wi-Fi data, such as SSID, channel, and BSSID. This enables the spectrum analyzer software to provide more context and insight into the spectrum activity and its impact on the Wi-Fi network. A firmware upgrade for the spectrum analysis adapter is not required for Wi-Fi integration, but it may be needed to fix bugs or add features to the device. A directional antenna is an antenna that focuses the RF energy in a specific direction and has a high gain and a narrow beamwidth. A directional antenna can be used with a spectrum analysis adapter to pinpoint the location or source of interference or noise in the wireless environment, but it is not required for Wi-Fi integration. SNMP read credentials to the WLAN controller or APs are not required for Wi-Fi integration, but they may be useful for obtaining additional information about the wireless network configuration and performance from the network devices. Reference:

CWAP-404 Study Guide, Chapter 4: Spectrum Analysis and Troubleshooting, page 123

CWAP-404 Objectives, Section 4.2: Integrate Wi-Fi data with spectrum analysis data

CWAP-404 Study Guide, Chapter 4: Spectrum Analysis and Troubleshooting, page 131

CWNP CWAP-404 Certified Wireless Analysis Professional Exam Practice Test