CWNP CWAP-403 問題集

質問 1：
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 customer should replace all their Bluetooth wireless mice as they are stopping the users on floor 5 from connecting to the wireless network
B. 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
C. 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
D. The customers APs are misbehaving and a technical support case should be open with the vendor
正解：A

質問 2：
You have installed a new 802.11ac 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 areA. 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?
A. The 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
B. Non Wi-Fi interference is preventing the APs 80 MHz operation
C. The AP is misconfigured and needs to be reconfigured to 80MHz operation
D. RRM is enabled and has dynamically picked a 20 MHz channel
正解：A

質問 3：
Which one of the following should be the first step when troubleshooting a WLAN issue?
A. Define the problem
B. Identify probable causes
C. Identify capture locations
D. Perform an initial WLAN scan and see if any obvious issues stand out
正解：A

質問 4：
Where, in a protocol analyzer, would you find an indication that a frame was transmitted as part of an AMPDU?
A. A-MPDU flag in the Frame Control Field
B. A-MPDU flag in the HT Control Field
C. The HT Operation Element
D. The Aggregation flag in the Radio Tap Header
正解：B

質問 5：
What is the function of the PHY Preamble?
A. Allows the receiver to detect and synchronize with the signal
B. Carries the NDP used in Transmit Beamforming and MU-MIMO
C. To terminate a conversation between transmitter and receiver
D. To set the modulation method for the MPDU
正解：A