CWAP-404問題集、CWNP実際の試験問題

質問 1

What two IEEE 802.11 entities may be used to separate successful transmissions within an EDCA TXOP? (Choose 2)

A. PIFS

B. SIFS

C. ACK

D. RIFS

E. AIFS

F. EIFS

G. CAP

正解: B,D

質問 2

You are attempting to determine timing information within a packet capture of a WLAN protocol analyzer.
What time is used to display the time the packet was captured based on the system clock in the computer?

A. Arrival

B. Relative

C. Delta

D. Interframe

正解: A

質問 3

When a client station operating under EDCA sends an RTS frame and NAV protection is desired for only the first or sole frame in the TXOP, the duration field will contain an amount of time, measured in microseconds, equal to which of the following?

A. 1 RTS, 1 CTS, 2 ACK , 1 DATA, 4 SIFS

B. 1 CTS, 2 ACK, 1 DATA, 2 SIFS

C. The entire duration of the TXOP

D. 1 CTS, 1 ACK, 1 DATA, 3 SIFS

E. 1 RTS, 1 ACK, 1 DATA, 2 SIFS, 1 DIFS

F. 1 RTS, 2 ACK, 1 DATA, 4 SIFS

正解: D

質問 4

Which statement accurately describes IEEE 802.11 Power Save operation in a Basic Service Set that does not support the QoS facility?

A. When the access point's buffer is full, the access point wakes all client stations using a PS-Poll frame so that they can receive the data.

B. Upon receiving traffic for a dozing station, the access point wakes the client station using a PS- Poll frame so that the client station can receive the data.

C. Following a period of time in a low power state, client stations wake themselves and automatically poll the access point for traffic using a PS-Poll frame.

D. After waking at a scheduled TBTT, client stations send Null Function frames to the access point with the Power Management bit set back to zero.

E. After waking from a low power state, client stations listen for the next Beacon to determine if sending a PS-Poll frame to the access point is necessary.

正解: E

質問 5

The PLCP sublayer provides framing by adding a header to create what type of data unit?

A. MPDU

B. PSDU

C. PPDU

D. MSDU

正解: C

解説: (PassTest メンバーにのみ表示されます)

質問 6

You must report on frame types seen on the WLAN. You want to list the frame types by both name and binary value.
What frame type is represented by the binary value 011010, which includes the Type and Subtype values?

A. Association Request

B. Beacon

C. PS-Poll

D. Authentication

正解: C

質問 7

According to the IEEE 802.11 standard, what is one structural difference between a MAC Protocol Data Unit (MPDU) and a MAC Management Protocol Data Unit (MMPDU)?

A. The MMPDU frame body is limited to 300 bytes, whereas the MPDU frame body can carry up to
2304 bytes.

B. An MMPDU header may only contain three address fields, but an MPDU may have four address fields.

C. The MPDU frame's FCS field is 4 bytes, while the MMPDU frame's FCS field is 8 bytes.

D. Both the MPDU and MMPDU have a QoS Control (QC) field, but all bits of the MMPDU's QC field are always 0.

E. The MPDU header always places the BSSID in the first address field, but in the MMPDU the BSSID can be found in any of the address fields.

正解: B

質問 8

What is the purpose of a PHY preamble?

A. It communicates important information about the PSDU's length, rate, and upper layer protocol- related parameters.

B. It provides a cyclic redundancy check (CRC) for the receiving station to validate that the PLCP header was received correctly.

C. It indicates to the PHY the modulation that shall be used for transmission (and reception) of the PSDU.

D. It provides the receiver(s) with an opportunity for RF channel synchronization prior to the start of the PLCP header.

正解: D

質問 9

Which statements are true regarding wireless network discovery and scanning processes for an HT network? (Choose 2)

A. Client stations send Probe Request frames on all HT channels in the 2.4 GHz ISM band in a consecutive manner until they receive at least 3 Probe Response frames.

B. Access points send Beacon frames only on the HT channel in the 2.4 GHz ISM band for which the access point is configured, and only after scanning that channel to discover existing BSSs.

C. Client stations may continually send Probe Request frames on all HT channels in the 2.4 GHz ISM band in a consecutive manner, regardless of their association state.

D. Access points send Beacon frames on all HT channels in the 2.4 GHz ISM band in a consecutive manner including the channel for which the access point is configured.

E. Client stations send Probe Request frames on all HT channels in the 2.4 GHz ISM band in a consecutive manner until they associate with an access point. After associating to an access point, they no longer transmit Probe Request frames.

正解: B,C

質問 10

What action is taken automatically by 802.11 APs and client STAs as the signal strength of the link weakens in order to improve the quality of the RF communications overall?

A. RSSI is increased

B. Antenna gain is increased

C. Data rates are reduced

D. Output power is increased

正解: C

質問 11

Given: ABC Company recorded the 2.4 GHz band with a spectrum analyzer prior to installing their ERP WLAN. Image-A is how the band appeared prior to the WLAN installation. Image-B is how the band appears now, and all channels on their WLAN have ceased to function.

What is the best explanation as to why their WLAN is no longer functioning properly?

A. A Terminal Doppler Weather Radar (TDWR) is causing a DFS response across the entire band.

B. A new microwave oven was installed in the cafeteria.

C. A malfunctioning IEEE 802.11 OFDM radio card is transmitting continuously.

D. A wideband RF power source is corrupting all IEEE 802.11 transmissions.

E. A manual site survey tool is actively testing the throughput of their WLAN.

正解: D

質問 12

A client is operating in an unstable RF environment. Out of five data frames transmitted to the client it only receives four. The client sends a Block Ack to acknowledge the receipt of these four frames but due to frame corruption the Block Ack is not received by the AP. Which frames will be transmitted?

A. Both the corrupted data and Block Ack

B. All data frames

C. Only the Block Ack

D. Only the data frame which was corrupted

正解: B

解説: (PassTest メンバーにのみ表示されます)

質問 13

In an HT WLAN in which a delayed Block Ack policy is set up, what should result when an ACK frame is not received by the originator in response to a Basic BlockAckReq?

A. All frames within that block must be retransmitted by the originator.

B. The last frame within that block must be retransmitted by the originator.

C. Nothing. No ACK is expected in response to a Basic BlockAckReq.

D. The BlockAckReq must be retransmitted by the originator.

正解: D

質問 14

As a wireless network consultant you have been called in to troubleshoot a high-priority issue for one of your customers. The customer's office is based on two floors within a multi-tenant office block. On one of these floors (floor 5) users cannot connect to the wireless network. During their own testing the customer has discovered that users can connect on floor 6 but not when they move to the floor 5. This issue is affecting all users on floor 5 and having a negative effect on productivity. To troubleshoot this issue, you perform both Spectrum and Protocol Analysis. The Spectrum Analysis shows the presence of Bluetooth signals which you have identified as coming from wireless mice. In the protocol analyzer you see the top frame on the network is Deauthentication frames. On closer investigation you see that the Deauthentication frames' source addresses match the BSSISs of your customers APs and the destination address is FF:FF:FF:FF:FF:FF:FF. What do you conclude from this troubleshooting exercise?

A. The users on floor 5 are being subjected to a denial of service attack, as this is happening across the entire floor it is likely to be a misconfigured WIPS solution belonging to the tenants on the floor below

B. The customers APs are misbehaving and a technical support case should be open with the vendor

C. The CCI from the APs on the floor 4 is the problem and you need to ask the tenant below to turn down their AP's Tx power

D. The customer should replace all their Bluetooth wireless mice as they are stopping the users on floor 5 from connecting to the wireless network

正解: A

解説: (PassTest メンバーにのみ表示されます)

CWNP Certified Wireless Analysis Professional - CWAP-404 模擬練習