CWNA V1.0 3 — Questions and Answers
Question 1: Which 802.11 security protocol uses SAE (Simultaneous Authentication of Equals) to replace the PSK handshake?
- WPA2-Personal
- WEP
- WPA3-Personal (Correct answer)
- TKIP
Correct answer: WPA3-Personal
WPA3-Personal replaced WPA2's 4-way PSK handshake with SAE, providing stronger protection against offline dictionary attacks.
Question 2: What is the maximum channel bandwidth introduced by 802.11ac (Wi-Fi 5) in the 5 GHz band?
- 40 MHz
- 80 MHz
- 160 MHz (Correct answer)
- 320 MHz
Correct answer: 160 MHz
802.11ac supports channel widths of up to 160 MHz (either contiguous or 80+80 MHz) in the 5 GHz band.
Question 3: Which WLAN architecture model places all intelligence and control functions on a centralized controller rather than in individual APs?
- Autonomous AP architecture
- Mesh AP architecture
- Centralized (controller-based) architecture (Correct answer)
- Distributed AP architecture
Correct answer: Centralized (controller-based) architecture
In centralized architecture, lightweight APs tunnel traffic to a WLAN controller that handles authentication, roaming, and policy enforcement.
Question 4: A site survey reveals a 'hidden node' problem. Which 802.11 mechanism is designed to mitigate this issue?
- CSMA/CA with RTS/CTS (Correct answer)
- MIMO beamforming
- Dynamic Frequency Selection (DFS)
- WMM power save
Correct answer: CSMA/CA with RTS/CTS
RTS/CTS (Request to Send/Clear to Send) frames alert all stations in range to defer transmission, reducing hidden node collisions.
Question 5: In the 2.4 GHz band, how many non-overlapping 20 MHz channels are available in the United States?
- 1
- 3 (Correct answer)
- 6
- 11
Correct answer: 3
Only channels 1, 6, and 11 are non-overlapping in the US 2.4 GHz band, giving 3 usable channels without co-channel interference.
Question 6: What is the role of the Distribution System (DS) in an 802.11 BSS infrastructure network?
- To encrypt client data using AES
- To connect multiple BSSs and provide access to external networks (Correct answer)
- To manage client roaming between SSIDs
- To transmit beacon frames on behalf of the AP
Correct answer: To connect multiple BSSs and provide access to external networks
The Distribution System is the backbone network (typically Ethernet) that interconnects BSSs and provides uplink to external networks.
Question 7: Which term describes the condition where two APs use the same channel and their coverage areas overlap, causing performance degradation?
- Adjacent-channel interference
- Co-channel interference (Correct answer)
- Multipath distortion
- Near-far problem
Correct answer: Co-channel interference
Co-channel interference occurs when multiple APs operate on the same channel within range of each other, forcing them to share medium access time.
CWNA V1.0 3
Which 802.11 security protocol uses SAE (Simultaneous Authentication of Equals) to replace the PSK handshake?