PW0-270 by CWAP Valid Free Exam Practice Test

Question 1

Which statements are true regarding frame acknowledgement in an IEEE 802.11 WLAN? (Choose 3)

A. A client station's Reassociation Request frames are only acknowledged with a Reassociation Response from the access point and not with an ACK frame. B. Probe request acknowledgement (sending of a Probe Response frame) is configurable in the access point and is always linked to SSID broadcast configuration in Beacons. C. In an EDCA BSS, encrypted Data frames are only acknowledged by client stations, never by access points. D. Data frame fragments are acknowledged individually (with an ACK frame). E. The RA field of ACK frames is always obtained from the Address 2 field in the corresponding frame being acknowledged. F. Following non-QoS Data frames with the More Fragments bit set to 1, the Duration/ID field of the ACK frame is set to a value equal to two SIFS plus the next Data fragment and its ACK.

Correct Answer: D,E,F

Question 2

What HT PPDU format is shown in the exhibit?

A. HT-mixed format B. HT-greenfield format C. Non-HT duplicate format D. Dual Training Field format E. Non-HT format F. ERP-OFDM format

Correct Answer: A

Question 3

Given: Before installing a Wi-Fi network, ABC Company performed a spectrum analysis looking for problems. The 2.4 GHz RF spectrum looked like Image-A. After installing an ERP WLAN, ABC Company performed another spectrum analysis during business hours. The 2.4 GHz RF spectrum then looked like Image-B close to an AP on channel 1.

Now the 2.4 GHz RF spectrum looks like Image-C and access points and clients can no longer communicate on channel 1. What is happening on channel 1?

A. The shape of the signals in images B and C indicates that a licensed user in this frequency range has enabled the "guard bands" in an effort to restrict local interference with other systems. B. Stronger transmissions from licensed 2.4 GHz users, such as HAM operators, are compressing the transmissions from the channel 1 access points into the lower portion of the band. C. A high-power, narrowband RF interference source on channel 1 is causing the CCA energydetects(ED) function on 802.11 devices to indicate a busy medium because the signal source is above the ED threshold. D. The access point's antenna connectors have been tampered with, causing "spike and shear" RF transmissions that are not compatible with the OFDM PHY format. For that reason, client devices cannot receive the AP's transmissions without error. E. Detection of a DFS radar event has discontinued 802.11 operation on channel 1, but the access point's Channel Switch Announcement frame cannot be sent due to the presence of radar.

Correct Answer: C

Question 4

In the analyzer trace shown, the TBTT is nominally 102.5 milliseconds.

Why does the Beacon transmission interval vary?

A. The DCF Interframe space (DIFS) is nominally 50 (us), but typically varies by as much as 10 (us), which causes delays in Beacons. B. This trace shows an HT network where HR/DSSS nodes are active on the network. The access point is changing slot times from short to long as needed. C. The access point must arbitrate to gain access to the RF medium in order to transmit a Beacon. D. Beacon frames vary in size, and therefore some take slightly longer to send than others.

Correct Answer: C

Question 5

In the frame decode shown, there are two sets of supported data rates. 1, 2, 5.5, and 11 Mbps are all shown as "basic" data rates, and 6, 9, 12, 18, 24, 36, 48, and 54 Mbps are shown simply as supported data rates.

What is true of "basic" data rates in this context?

A. The highest data rate set to Basic is automatically used to send broadcast traffic such as Beacon frames. B. Basic rates are defined in an AP's service set to specify mandatory data rates for all retry frames. C. Basic rates are optional data rates for the BSS, often used for assuring connectivity for legacy stations. D. Basic rates are only used for multicast traffic, and do not affect unicast traffic. E. The AP requires all client stations to support Basic rates in order to associate to its BSS.

Correct Answer: E

Question 6

To effect Preauthentication, a STA's supplicant sends an IEEE 802.1X/EAPoL Start message. How is the EAPoL Start message addressed?

A. DA = BSSID of the targeted AP; RA = Ethernet MAC of the targeted AP B. DA = BSSID of targeted AP; RA = BSSID of the AP to which the STA is associated C. DA = MAC of the default gateway; RA = Ethernet MAC of the targeted AP D. DA = MAC of default gateway; RA = BSSID of the AP to which the STA is associated

Correct Answer: B

CWAP Certified Wireless Analysis Professional - PW0-270 Exam Practice Test