Download Certified Wireless Analysis Professional Exam.CWAP-404.VCEDumps.2024-03-28.31q.vcex

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.Reference:[Wireless Analysis Professional Study Guide CWAP-404], Chapter 4: 802.11 Physical Layer, page 97-98

The function of the PHY layer is to convert PSDUs to PPDUs for transmissions and PPDUs to PSDUs for receptions. A PSDU (PHY Service Data Unit) is the data unit that is passed from the MAC layer to the PHY layer for transmission, or from the PHY layer to the MAC layer for reception. 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 and a PHY header, which contains information such as modulation, coding, and data rate. The PHY layer adds or removes the PHY header to or from the PSDU during the conversion process.Reference:[Wireless Analysis Professional Study Guide CWAP-404], Chapter 4: 802.11 Physical Layer, page 97-98

The function of the PHY preamble is to allow the receiver to detect and synchronize with the signal. 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 adjust its parameters, such as frequency, timing, and gain, to match the incoming signal. The PHY preamble also helps the receiver to estimate the channel conditions and noise level.Reference:[Wireless Analysis Professional Study Guide CWAP-404], Chapter 4: 802.11 Physical Layer, page 99-100

The first step in any troubleshooting process is to define the problem. This involves gathering information from various sources, such as users, network administrators, network documentation, and network monitoring tools.Defining the problem helps to narrow down the scope of the issue and identify the symptoms, causes, and effects of the problem12Reference:CWAP-403 Study Guide, Chapter 1: Troubleshooting Methodology, page 7CWAP-403 Objectives, Section 1.1: Define the problem

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 displayfilter.This is an advantage over capture-time filters, which discard the packets that do not match the filter criteria and cannot be recovered later34Reference:CWAP-403 Study Guide, Chapter 2: Protocol Analysis, page 37CWAP-403 Objectives, Section 2.3: Apply display filters

Receive sensitivity is the minimum signal level that a receiver can detect and decode. Different devices may have different receive sensitivity levels depending on their hardware specifications and antenna configurations. In this scenario, the portable analyzer has a lower receive sensitivity than the AP, meaning that it requires a stronger signal to capture the packets from the client STA. The AP, on the other hand, has a higher receive sensitivity and can receive the packets from the client STA even if they have a weaker signal.This explains why the portable analyzer can only see unidirectional traffic from the AP to the client when capturing near the AP5Reference:CWAP-403 Study Guide, Chapter 4: PHY Layer Analysis, page 121CWAP-403 Objectives, Section 4.3: Analyze PHY layer metrics

The 4-way handshake is the process that establishes the pairwise transient key (PTK) between the client and the AP in WPA2-PSK. The PTK is derived from the PSK, the SSID, and some random numbers exchanged in the handshake frames. The PTK is used to encrypt and decrypt the data frames between the client and the AP.Therefore, in order to decrypt WPA2-PSK data packets, a protocol analyzer needs to capture the 4-way handshake frames and have the PSK and SSID configured in the analyzer software12Reference:CWAP-404 Study Guide, Chapter 3: 802.11 MAC Layer Frame Formats and Technologies, page 87CWAP-404 Objectives, Section 3.5: Analyze security exchanges

Real-time packet decodes are not a consideration when configuring a long-term, forensic packet capture and saving all packets to disk. Real-time packet decodes are useful for live analysis and troubleshooting, but they consume CPU and memory resources that could affect the performance of the capture process. For a long-term, forensic packet capture, it is more important to consider the analyzer location, the total capture storage space, and the individual trace file size.These factors affect the quality and quantity of the captured packets and the ease of post-capture analysis34Reference:CWAP-404 Study Guide, Chapter 2: Protocol Analysis, page 49CWAP-404 Objectives, Section 2.1: Configure protocol analyzers

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 captured5Reference:CWAP-404 Study Guide, Chapter 2: Protocol Analysis, page 57CWAP-404 Objectives, Section 2.4: Analyze timing values

A hexadecimal value is a value that uses base 16 notation, which means it can have digits from 0 to 9 and letters from A to F. A hexadecimal value is usually preceded by 0x to indicate that it is hexadecimal and not decimal or binary. For example, 0x0A is hexadecimal for 10 in decimal or 00001010 in binary. The other options are not valid prefixes for hexadecimal values.Reference:CWAP-404 Study Guide, Chapter 2: Protocol Analysis, page 35CWAP-404 Objectives, Section 2.2: Analyze field values