CWNA V1.0 5 — Questions and Answers
Question 1: A CWNA candidate must configure a 5 GHz channel that avoids interfering with weather radar systems. Which feature handles this automatically?
- Transmit Power Control (TPC)
- Dynamic Frequency Selection (DFS) (Correct answer)
- Beamforming
- Band Steering
Correct answer: Dynamic Frequency Selection (DFS)
DFS requires APs to monitor for radar signals on certain 5 GHz channels and vacate the channel within 10 seconds if radar is detected.
Question 2: Which component of the 802.11i security standard is responsible for generating and managing the keys used to encrypt unicast data frames?
- 4-Way Handshake (Correct answer)
- Group Key Handshake
- EAP-TLS
- CCMP
Correct answer: 4-Way Handshake
The 4-Way Handshake derives and confirms the PTK (Pairwise Transient Key) used to encrypt unicast traffic between a client and AP.
Question 3: What is the Fresnel Zone and why does it matter for outdoor point-to-point wireless links?
- A regulatory exclusion zone around military frequencies
- An elliptical RF propagation region that must remain 60% clear of obstructions (Correct answer)
- The area of maximum interference between two APs
- A buffer zone required between omni and directional antennas
Correct answer: An elliptical RF propagation region that must remain 60% clear of obstructions
The Fresnel Zone is an elliptical region around the line-of-sight path; obstruction of more than 40% causes significant signal loss through diffraction.
Question 4: A hospital wants to deploy a WLAN for medical devices that cannot tolerate packet loss. Which 802.11 feature allows an AP to signal clients about its neighbor APs to assist in roaming decisions?
- 802.11r Fast BSS Transition
- 802.11k Neighbor Report (Correct answer)
- 802.11v BSS Transition Management
- 802.11u Interworking
Correct answer: 802.11k Neighbor Report
802.11k allows APs to provide clients with a neighbor report listing nearby APs, enabling clients to make faster and more informed roaming decisions.
Question 5: In passive site survey methodology, what is the MAIN activity performed by the surveyor?
- Generating test traffic to measure throughput at each location
- Listening and recording RF signals without transmitting (Correct answer)
- Associating client devices and running iPerf benchmarks
- Placing APs and measuring overlap percentages
Correct answer: Listening and recording RF signals without transmitting
A passive survey uses a WLAN adapter in monitor mode to capture RF data without connecting to any network, ideal for assessing existing interference.
Question 6: Which IEEE standard defines the CAPWAP (Control and Provisioning of Wireless Access Points) protocol used for AP-controller communication?
- RFC 4118
- RFC 5415 (Correct answer)
- IEEE 802.11ac
- IEEE 802.3af
Correct answer: RFC 5415
RFC 5415 defines CAPWAP, which standardizes the tunnel protocol between lightweight APs and WLAN controllers across different vendors.
Question 7: What is the significance of the -82 dBm receiver sensitivity threshold commonly referenced in WLAN design?
- It is the maximum legal EIRP in the US for 2.4 GHz
- It is the minimum signal level at which most clients can maintain a basic 1 Mbps connection (Correct answer)
- It is the noise floor threshold below which 802.11ax APs stop transmitting
- It is the channel switch announcement threshold for DFS channels
Correct answer: It is the minimum signal level at which most clients can maintain a basic 1 Mbps connection
Receiver sensitivity near -82 dBm typically corresponds to the lowest supported data rate, meaning signals weaker than this cannot maintain a connection.
CWNA V1.0 5
A CWNA candidate must configure a 5 GHz channel that avoids interfering with weather radar systems.
Which feature handles this automatically?