The CWAP-404 PDF Dumps Greatest for the CWNP Exam Study Guide!
Read Online CWAP-404 Test Practice Test Questions Exam Dumps
CWNP CWAP-404 Exam Topics:
| Section | Objectives |
|---|---|
Protocol Analysis - 15% | |
| Capture 802.11 frames using the appropriate methods | - Select capture devices
- Install monitor mode drivers |
| Understand and apply the common capture configuration parameters available in protocol analysis tools | - Save to disk - Packet slicing - Event triggers - Buffer options - Channels and channel widths - Capture filters - Channel scanning and dwell time |
| Analyze 802.11 frame captures to discover problems and find solutions | - Use appropriate display filters to view relevant frames and packets - Use colorization to highlight important frames and packets - Configure and display columns for analysis purposes - View frame and packet decodes while understanding the information shown and applying it to the analysis process - Use multiple adapters and channel aggregation to view captures from multiple channels - Implement protocol analyzer decryption procedures - View and use a capture’s statistical information for analysis - Use expert mode for analysis - View and understand peer maps as they relate to communications analysis |
| Utilize additional tools that capture 802.11 frames for analysis and troubleshooting | - WLAN scanners and discovery tools - Protocol capture visualization and analysis tools - Centralized monitoring, alerting, and forensic tools |
| Ensure appropriate troubleshooting methods are used with all analysis types | - Define the problem - Determine the scale of the problem - Identify probable causes - Capture and analyze the data - Observe the problem - Choose appropriate remediation steps - Document the problem and resolution |
Spectrum Analysis - 10% | |
| Capture RF spectrum data and understand the common views available in spectrum analyzers | - Install, configure, and use spectrum analysis software and hardware - Capture RF spectrum data using handheld, laptop-based, and infrastructure spectrum capture solutions - Understand and use spectrum analyzer views
|
| Analyze spectrum captures to identify relevant RF information and issues | - RF noise floor in an environment - Signal-to-Noise Ratio (SNR) for a given signal - Sources of RF interference and their locations - RF channel utilization - Non-Wi-Fi transmitters and their impact on WLAN communications - Overlapping and non-overlapping adjacent channel interference - Poor performing or faulty radios |
| Analyze spectrum captures to identify various device signatures | - Identify various 802.11 PHYs
- Identify non-802.11 devices based on RF behaviors and signatures
|
| Use centralized spectrum analysis solutions | - AP-based spectrum analysis - Sensor-based spectrum analysis |
PHY Layers and Technologies - 10% | |
| Understand and describe the functions of the PHY layer and the PHY protocol data units (PPDUs) | - DSSS (Direct Sequence Spread Spectrum) - HR/DSSS (High Rate/Direct Sequence Spread Spectrum) - OFDM (Orthogonal Frequency Division Multiplexing) - ERP (Extended Rate PHY) - HT (High Throughput) - VHT (Very High Throughput) - HE (High Efficiency)
|
| Apply the understanding of PHY technologies, including PHY headers, preambles, training fields, frame aggregation, and data rates, to captured data | |
| Identify and use PHY information provided within pseudo-headers in protocol analyzers | - Pseudo-Header formats
- Key pseudo-header content
|
| Recognize the limits of protocol analyzers to capture PHY information including NULL data packets and PHY headers | |
CWNP CWAP-404 Exam Certification Details:
| Exam Price | $275 USD |
| Number of Questions | 60 |
| Exam Code | CWAP-404 CWAP |
| Passing Score | 70% |
| Sample Questions | CWNP CWAP-404 Sample Questions |
NEW QUESTION # 37
Which one of the these is the most important in the WLAN troubleshooting methodology among those listed?
- A. Obtain detailed -knowledge of the wireless vendors debug and logging options
- B. Interview the network manager about the issues being experienced
- C. Observe the problem
- D. Talk to the end users about their experiences
Answer: C
Explanation:
Explanation
Observing the problem is the most important step in the WLAN troubleshooting methodology among those listed. This step involves capturing and analyzing the relevant data from the wireless network, such as packets, frames, spectrum, and performance metrics. Observing the problem helps to verify the existence and scope of the issue, identify the root cause and possible solutions, and validate the results of any actions taken. The other steps are also important, but they are not as critical as observing the problem12 References:
CWAP-404 Study Guide, Chapter 1: Troubleshooting Methodology, page 15
CWAP-404 Objectives, Section 1.2: Observe the problem
NEW QUESTION # 38
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?
- A. Ask 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
- B. Access the microwave remotely and run a diagnostic check
- C. Ask a local member of staff to change the frequency of the microwave and see if the disconnections stop
- D. Place one of the London APs into spectrum analyzer mode and monitor the situation over lunch time
Answer: D
Explanation:
Explanation
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 tothe microwave or any changes to its frequency. References: [Wireless Analysis Professional Study Guide], Chapter 3: Spectrum Analysis, page 64
NEW QUESTION # 39
After examining a Beacon frame decode you see the SSID Element has a length of 0. What do you conclude about this frame?
- A. SSID elements always have a length of 0
- B. The frame is corrupted
- C. The beacon is from a BSS configured to hide the SSID
- D. This is a common attack on WISP backend SQL databases
Answer: C
Explanation:
Explanation
If the SSID element has a length of 0 in a Beacon frame decode, it means that the beacon is from a BSS configured to hide the SSID. The SSID element is a part of the Beacon frame that contains the name or identifier of the BSS. The SSID element has two fields: length and value. The length field indicates how many bytes are used for the value field, which contains the actual SSID string. If the length field is 0, it means that there is no value field or SSID string in the element. This is a common technique used by some APs to hide their SSID from passive scanning clients or potential attackers. However, this technique does not provide much security, as there are other ways to discover or reveal the hidden SSID, such as active scanning or capturing probe response or association frames. References: [Wireless Analysis Professional Study Guide CWAP-404], Chapter 5: 802.11 MAC Sublayer, page 122-123
NEW QUESTION # 40
Which one of the following statements is not true concerning DTIMs?
- A. Buffered Broadcast and Multicast traffic will be transmitted following a DTIM
- B. The DTIM interval can dictate when an STA will wake up to listen to beacon frames
- C. Every Beacon frame must contain a DTIM
- D. DTIM stands for Delivery Traffic Indication Map
Answer: C
Explanation:
Explanation
Every Beacon frame must contain a DTIM is not a true statement concerning DTIMs. DTIM stands for Delivery Traffic Indication Message, and it is a subfield within the TIM (Traffic Indication Map) element in a Beacon frame. The DTIM indicates how many Beacon frames (including the current one) will appear before the next DTIM. For example, if the DTIM interval is set to 3, it means that every third Beacon frame will contain a DTIM. Buffered broadcast and multicast traffic will be transmitted following a DTIM, so that STAs in power save mode can wake up and receive them. The DTIM interval can also dictate when an STA will wake up to listen to Beacon frames, as some STAs may choose to only listen to Beacon frames that contain a DTIM . References: CWAP-404 Certified Wireless Analysis Professional Study and Reference Guide, Chapter
6: MAC Sublayer Frame Exchanges, page 200; CWAP-404 CertifiedWireless Analysis Professional Study and Reference Guide, Chapter 6: MAC Sublayer Frame Exchanges, page 201.
NEW QUESTION # 41
Which one of the following is an advantage of using display filters that is not an advantage of capture-time filters?
- A. They allow for focused analysis on just the packets of interest
- B. They only hide the packets from view and the filtered packets can be enabled for view later
- C. Multiple of them can be applied simultaneously
- D. Once created they are reusable for later captures
Answer: B
Explanation:
Explanation
Display filters are applied after the capture is completed and they only hide the packets from view. The filtered packets are still present in the capture file and can be enabled for view later by changing or removing the display filter. This is an advantage over capture-time filters, which discard the packets that do not match the filter criteria and cannot be recovered later34 References:
CWAP-403 Study Guide, Chapter 2: Protocol Analysis, page 37
CWAP-403 Objectives, Section 2.3: Apply display filters
NEW QUESTION # 42
The PHY layer provides framing by adding a header to create what type of data unit?
- A. PPDU
- B. MSDU
- C. MPDU
- D. PSDU
Answer: A
Explanation:
Explanation
The PHY layer provides framing by adding a header to create a PPDU. A PPDU (PHY Protocol Data Unit) is the data unit that is transmitted or received over the wireless medium by the PHY layer. A PPDU consists of a PSDU (PHY Service Data Unit) and a PHY header, which contains information such as modulation, coding, and data rate. The PHY layer adds the PHY header to the PSDU to create a PPDU for transmission, or removes the PHY header from the PPDU to extract the PSDU for reception. The other options are not correct, as they are not created by adding a header at the PHY layer. An MPDU (MAC Protocol Data Unit) is created by adding a MAC header and FCS to an MSDU (MAC Service Data Unit) at the MAC layer. An MSDU is the data unit that is passed from the LLC sublayer to the MAC sublayer or vice versa. References: [Wireless Analysis Professional Study Guide CWAP-404], Chapter 4: 802.11 Physical Layer, page 97-98
NEW QUESTION # 43
You are performing a multiple adapter channel aggregation capture to troubleshoot a VoIP roaming problem and would like to measure the roaming time from the last VoIP packet sent on the old AP's channel to the first VoIP packet sent on the new AP's channel. Which timing column in the packet view would measure this for you?
- A. Delta
- B. Absolute
- C. Roaming
- D. Relative
Answer: A
Explanation:
Explanation
Delta is the timing column in the packet view that measures the time difference between two consecutive packets in a capture file. Delta can be used to measure the roaming time from the last VoIP packet sent on the old AP's channel to the first VoIP packet sent on the new AP's channel by selecting these two packets and looking at their delta values. The other timing columns are not suitable for this measurement because they do not show the time difference between two specific packets. Roaming is a column that shows whether a packet belongs to a roaming event or not. Relative is a column that shows the time elapsed since the beginning of the capture file. Absolute is a column that shows the date and time when a packet was captured5 References:
CWAP-404 Study Guide, Chapter 2: Protocol Analysis, page 57
CWAP-404 Objectives, Section 2.4: Analyze timing values
NEW QUESTION # 44
When performing protocol analysis, you capture an 802.1 lac data frame on channel 52, transmitted at MCS 8.
At what data rate was the PHY Preamble transmitted?
- A. 6 Mbps
- B. 78 Mbps
- C. 54 Mbps
- D. 86.7 Mbps
Answer: A
Explanation:
Explanation
The data rate at which the PHY preamble was transmitted is 6 Mbps. The PHY preamble is a part of the PPDU that is transmitted before the PHY header and the PSDU. The PHY preamble consists of a series of training fields that help the receiver to detect and synchronize with the signal. The PHY preamble is always transmitted at a fixed data rate that depends on the type of PPDU (e.g., OFDM, HT, VHT, HE). For an 802.1 lac data frame on channel 52, which uses VHT PPDUs, the data rate for the PHY preamble is 6 Mbps. This data rate does not depend on MCS (Modulation and Coding Scheme), which only affects the data rate for the PSDU. References: [Wireless Analysis Professional Study Guide CWAP-404], Chapter 4: 802.11 Physical Layer, page 99-100
NEW QUESTION # 45
In which element of a Beacon frame would you look to identity the current HT protection mode in which an AP is operating?
- A. HT Capabilities Element
- B. HT Protection Element
- C. ERP Information Element
- D. HT Operations Element
Answer: D
Explanation:
Explanation
The HT protection mode in which an AP is operating can be identified by looking at the HT Operations element in a Beacon frame. The HT Operations element is a part of the Beacon frame that contains information about the High Throughput (HT) capabilities and operation of an 802.11n BSS. The HT Operations element has a field called HT Protection, which indicates how the BSS protects its HT transmissions from interference or collisions with non-HT devices or BSSs. The HT Protection field can have four values: No Protection, Nonmember Protection, 20 MHz Protection, or Non-HT Mixed Mode. The other options are not correct, as they do not contain information about the HT protection mode. The HT Protection element does not exist, the ERP Information element is used for Extended Rate PHY (ERP) protection mode for 802.11g devices, and the HT Capabilities element is used for indicating the supported HT features of an individual device. References: [Wireless Analysis Professional Study Guide CWAP-404], Chapter 5: 802.11 MAC Sublayer, page 125-126
NEW QUESTION # 46
Which piece of information is not transmitted in an HT PPDU header?
- A. PPDU length
- B. Channel number
- C. Number of Spatial Streams
- D. MCS index
Answer: B
Explanation:
Explanation
The channel number is not transmitted in an HT PPDU header. An HT PPDU header is a part of the PPDU that contains information such as modulation, coding, data rate, and number of spatial streams for an 802.11n transmission. The channel number is not included in the HT PPDU header, as it is determined by the frequency band and channel width that are used by the transmitter and receiver. The channel number can be inferred from the frequency band and channel width, which are indicated by bits in different fields of the HT PPDU header, such as HT-SIG and HT-LTF. The other options are not correct, as they are transmitted in an HT PPDU header. The number of spatial streams, PPDU length, and MCS index are indicated by bits in the HT-SIG field of the HT PPDU header. References: [Wireless Analysis Professional Study Guide CWAP-404], Chapter 4: 802.11 Physical Layer, page 108-109
NEW QUESTION # 47
Where would you look in a packet trace file to identify the configured Minimum Basic Rate (MBR) of a BSS?
- A. In the MBR Information Element in an Association Response frame
- B. In the MBR Action frame
- C. In the Minimum Basic Rate Element in a Beacon frame
- D. Supported Rates & Extended Supported Rates elements in a Beacon frame
Answer: D
Explanation:
Explanation
The configured Minimum Basic Rate (MBR) of a BSS can be identified by looking at the Supported Rates and Extended Supported Rates elements in a Beacon frame. A Beacon frame is a type of management frame that is transmitted by an AP to advertise its presence and capabilities to potential clients. A Beacon frame contains various information elements (IEs) that provide details about the BSS configuration and operation. The Supported Rates andExtended Supported Rates IEs list the data rates that are supported by the AP for data transmission. The MBR is the lowest data rate among these supported rates that is required for all clients to join and communicate with the BSS. The MBR is usually marked with a flag bit in these IEs to indicate its mandatory status. The other options are not correct, as they do not exist or do not indicate the MBR of a BSS. References: [Wireless Analysis Professional Study Guide CWAP-404], Chapter 5: 802.11 MAC Sublayer, page 123-124
NEW QUESTION # 48
What is an AIFS?
- A. A medium access method introduced by 802.lln, but never implemented
- B. A variable Interframe Space introduced by 802.lie to help prioritize medium access for different Access Categories
- C. The shortest period of time a STA can sleep
- D. A form of aggregation performed at the PHY layer based on 802.lie UP values interpreted from DSCP values
Answer: B
Explanation:
Explanation
An AIFS is a variable interframe space introduced by 802.11e to help prioritize medium access for different Access Categories (ACs). An interframe space is a period of time that a STA (station) has to wait before attempting to access the medium. An AIFS is a type of interframe space that varies depending on the AC of the traffic. An AC is a logical queue that corresponds to a QoS (Quality of Service) level for different types of traffic. There are four ACs defined by 802.11e: AC_VO (Voice), AC_VI (Video), AC_BE (Best Effort), and AC_BK (Background). Each AC has a different AIFSN (Arbitration Interframe Space Number) value, which determines how long it has to wait before attempting to access the medium. A lower AIFSN value means a higher priority and a shorter waiting time. The other options are not correct, as they do not describe what an AIFS is. An AIFS is not a medium access method introduced by 802.11n, but never implemented, as it is part of the 802.11e standard and widely used in QoS-enabled WLANs. An AIFS is not a form of aggregation performed at the PHY layer based on 802.11e UP values interpreted from DSCP values, as aggregation is a technique that combines multiple frames into one larger frame to improve efficiency and throughput, not prioritization or medium access. An AIFS is not the shortest period of time a STA can sleep, as sleeping is a power saving mode that allows a STA to conserve battery power by periodically turning off its radio, not accessing the medium. References: [Wireless Analysis Professional Study Guide CWAP-404], Chapter 7: QoS Analysis, page 194-195
NEW QUESTION # 49
Given: The Frame Check Sequence (FCS) is a 32 CRC used for error detection.
The CRC is calculated over what?
- A. Mac Header and Frame Body only
- B. PHY Header, MAC Header and Frame Body
- C. PHY Header and Mac Header only
- D. Frame Body only
Answer: A
Explanation:
Explanation
The CRC is calculated over the MAC Header and Frame Body only. The CRC (Cyclic Redundancy Check) is a 32-bit value that is used for error detection in wireless transmissions. The CRC is calculated over the MAC Header and Frame Body of a PSDU, which are the parts of the data unit that contain information such as source and destination addresses, frame type, frame control, sequence number, payload, etc. The CRC is appended to the end of the PSDU as a FCS (Frame Check Sequence) field. The CRC is not calculated over the PHY Header or PHY Preamble, which are parts of the PPDU that contain information such as modulation, coding, data rate, etc. The PHY Header and PHY Preamble are added or removed by the PHY layer during the conversion between PSDU and PPDU. References: [Wireless Analysis Professional Study Guide CWAP-404], Chapter 4: 802.11 Physical Layer, page 97-98
NEW QUESTION # 50
When a data frame is encrypted with WPA2, to which portion of the frame is the encryption applied?
- A. Frame body excluding the LLCPDU
- B. Frame body including the LLCPDU
- C. The whole MPDU
- D. Frame body and MAC Header
Answer: B
Explanation:
Explanation
When a data frame is encrypted with WPA2, the encryption is applied to the frame body including the LLCPDU. The LLCPDU (Logical Link Control Protocol Data Unit) is a part of the frame body that contains information such as protocol type, source and destination service access points (SAPs), and control fields. The LLCPDU is added by the LLC (Logical Link Control) sublayer to provide multiplexing and flow control functions for different upper layer protocols. When a data frame is encrypted with WPA2, which uses AES-CCMP as its encryption algorithm, both the payload and the LLCPDU are encrypted as a single unit. The MAC header and FCS are not encrypted, as they are needed for addressing and error detection purposes. References: [Wireless Analysis Professional Study Guide CWAP-404], Chapter 5: 802.11 MAC Sublayer, page 115-116
NEW QUESTION # 51
In a Spectrum Analyzer the Swept Spectrogram plot displays what information?
- A. Reductions in frame transmissions
- B. RF power present at a particular frequency over the course of time
- C. Wi-Fi Device information
- D. The RF time domain
Answer: B
Explanation:
Explanation
The Swept Spectrogram plot is a spectrum analysis plot that shows the RF power present at a particular frequency over the course of time. It can help identify trends and patterns in the RF spectrum over a longer period of time. It can also show how the RF environment changes over time and how different sources of RF signals affect each other. The other options are not correct, as they describe different types of plots or information that are not related to the Swept Spectrogram plot. References: [Wireless Analysis Professional Study Guide], Chapter 3: Spectrum Analysis, page 72-73
NEW QUESTION # 52
When would you expect to see a Reassociation Request frame'
- A. Every time a STA roams
- B. Every time a STA associates to an AP to which it has previously been associated
- C. Only when a STA is using FT roaming
- D. Only when a STA roams back to an AP it has previously been associated with
Answer: A
Explanation:
Explanation
A Reassociation Request frame is sent every time a STA roams from one AP to another within the same ESS.
A Reassociation Request frame is similar to an Association Request frame, but it also contains the BSSID of the current AP that the STA is leaving. This allows the new AP to coordinate with the old AP and transfer the STA's context information, such as security keys, QoS parameters, and buffered frames. This way, the STA can maintain its connectivity and session continuity during roaming . References: CWAP-404 Certified Wireless Analysis Professional Study and Reference Guide, Chapter 6: MAC Sublayer Frame Exchanges, page 195;CWAP-404 Certified Wireless Analysis Professional Study and Reference Guide, Chapter 6: MAC Sublayer Frame Exchanges, page 196.
NEW QUESTION # 53
The network administrator at ABC Engineering has taken a large packet capture from one of their APs running in monitor mode. She has very little knowledge of 802.11 protocols but would like to use the capture file to evaluate the overall health and performance of their wireless network. When she asks your advice, which tool do you recommend she opens the packet capture file with?
- A. Capture visualization tool
- B. WLAN scanner
- C. Spectrum analyzer
- D. Python
Answer: A
Explanation:
Explanation
A capture visualization tool is a software application that can open a packet capture file and display various graphs, charts, tables, and statistics that illustrate the characteristics and behavior of the wireless network. A capture visualization tool can help a network administrator with little knowledge of 802.11 protocols to evaluate the overall health and performance of their wireless network by providing a visual and intuitive representation of the captured data. A spectrum analyzer is a hardware device that measures the radio frequency signals in a given frequency range and displays their amplitude, frequency, and modulation. A spectrum analyzer can help identify sources of interference and noise in the wireless environment, but it cannot open a packet capture file. Python is a programming language that can be used to write scripts or applications that manipulate or analyze packet capture files, but it requires coding skills and knowledge of
802.11 protocols. A WLAN scanner is a software application that scans for available wireless networks and displays information such as SSID, BSSID, channel, signal strength, security type, and vendor. A WLAN scanner can help discover wireless networks and their basic parameters, but it cannot open a packet capture file345 References:
CWAP-404 Study Guide, Chapter 2: Protocol Analysis, page 63
CWAP-404 Objectives, Section 2.5: Use capture visualization tools
CWAP-404 Study Guide, Chapter 4: Spectrum Analysis and Troubleshooting, page 117 CWAP-404 Objectives, Section 4.1: Use spectrum analysis tools CWAP-404 Study Guide, Chapter 2: Protocol Analysis, page 33 CWAP-404 Objectives, Section 2.2: Analyze field values
NEW QUESTION # 54
ABC International has installed a new smart ZigBee controlled lighting system. However, the network team is concerned that this new system will interfere with the existing WLAN and has asked you to investigate the impact of the two systems operating simultaneously in the 2.4 GHz band. When performing Spectrum Analysis, which question could you answer by looking at the FFT plot?
- A. Is the ZigBee system using more than 50% of the available airtime?
- B. Do the ZigBee channels used by the lighting system overlap with the WLAN channels?
- C. Is the ZigBee system causing an increase in WLAN retries?
- D. Is the WLAN corrupting ZigBee system messages?
Answer: B
Explanation:
Explanation
The FFT plot is a spectrum analysis plot that shows the RF power present at a particular frequency over a short period of time. It can help identify the sources and characteristics of RF signals in the spectrum. By looking at the FFT plot, you can determine which ZigBee channels are used by the lighting system and whether they overlap with the WLAN channels in the 2.4 GHz band. ZigBee channels are 5 MHz wide and WLAN channels are 20 MHz or 40 MHz wide, so there is a possibility of overlap and interference between them. The other questions cannot be answered by looking at the FFT plot alone, as they require other types of plots or analysis tools, such as duty cycle plot, airtime utilization plot, or protocol analyzer. References: [Wireless Analysis Professional Study Guide], Chapter 3: Spectrum Analysis, page 69-70
NEW QUESTION # 55
Which common feature of a Spectrum Analyzer would be the best to help you locate a non-802.11 interference source?
- A. Device finder
- B. Location filter
- C. Min hold
- D. Max hold
Answer: A
Explanation:
Explanation
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. References: [Wireless Analysis Professional Study Guide CWAP-404], Chapter 3: Spectrum Analysis, page 77-78
NEW QUESTION # 56
You are troubleshooting a client that is experiencing slow WLAN performance. As part of the troubleshooting activity, you start a packet capture on your laptop close to the client device. While analyzing the packets, you suspect that you have not captured all packets transmitted by the client. By analyzing the trace file, how can you confirm if you have missing packets?
- A. Protocol Analyzers show the number of missing packets in their statistics view
- B. Look for gaps in the sequence number in MAC headers.
- C. The missing packets will be shown as CRC errored packets
- D. Retransmission are an indication of missing packets
Answer: B
Explanation:
Explanation
One way to confirm if you have missing packets in your packet capture is to look for gaps in the sequence number in MAC headers. The sequence number is a 12-bit field in the MAC header that is used to identify and order data frames within a traffic stream. The sequence number is incremented by one for each new data frame transmitted by a STA, except for retransmissions, fragments, and control frames. The sequence number can range from 0 to 4095, and then wraps around to 0. If you see a jump or a gap in the sequence number between two consecutive data frames from the same STA, it means that you have missed some packets in between. The other options are not correct, as they do not confirm if you have missing packets in your packet capture. CRC errored packets are packets that have been corrupted during transmission and have failed the error detection check. Protocol analyzers may show the number of CRC errored packets in their statistics view, but not the number of missing packets. Retransmissions are an indication of packet loss or collision, but not necessarily of missing packets in your capture. References: [Wireless Analysis Professional Study Guide CWAP-404], Chapter 5: 802.11 MAC Sublayer, page 114-115
NEW QUESTION # 57
......
CWAP-404 Certification All-in-One Exam Guide Jan-2024: https://www.examcost.com/CWAP-404-practice-exam.html
Easily To Pass New CWAP-404 Premium Exam: https://drive.google.com/open?id=1i1uGZdpFVW-wJe0CaPga03Z0oNSoeM-M
