ACA Wireless Technologies 3 — Questions and Answers
Question 1: What is the function of the Aruba AP's 'air monitor' mode?
- It serves client traffic on a dedicated SSID
- It passively monitors the RF environment without serving clients (Correct answer)
- It bridges wired and wireless networks
- It acts as a backup controller
Correct answer: It passively monitors the RF environment without serving clients
An Aruba AP in air monitor (AM) mode scans the RF environment for rogue APs and interference without serving client traffic.
Question 2: Which 802.11 power management feature allows an AP to buffer frames for sleeping clients and notify them via TIM?
- WMM Power Save
- Legacy Power Save (PS-Poll) (Correct answer)
- APSD
- Target Wake Time (TWT)
Correct answer: Legacy Power Save (PS-Poll)
Legacy Power Save uses PS-Poll frames; the AP buffers frames and uses the Traffic Indication Map (TIM) in beacons to alert sleeping clients.
Question 3: In an Aruba network, what protocol is used between a campus AP and a Mobility Controller to tunnel client traffic?
- IPsec
- CAPWAP
- GRE (Correct answer)
- MPLS
Correct answer: GRE
Aruba uses GRE (Generic Routing Encapsulation) tunnels between APs and the Mobility Controller to carry client traffic centrally.
Question 4: What is the role of a Spectrum Analyzer in wireless network troubleshooting?
- It decodes 802.11 management frames
- It identifies non-802.11 RF interference sources in the spectrum (Correct answer)
- It maps IP addresses to wireless clients
- It generates synthetic traffic to test throughput
Correct answer: It identifies non-802.11 RF interference sources in the spectrum
A spectrum analyzer identifies non-802.11 RF sources such as microwave ovens, cordless phones, and Bluetooth that cause interference.
Question 5: Which 802.11 frame type is responsible for carrying user data between a wireless client and an AP?
- Management frames
- Control frames
- Data frames (Correct answer)
- Action frames
Correct answer: Data frames
Data frames carry actual user payload (such as IP packets) between wireless clients and the AP.
Question 6: What is the primary advantage of MU-MIMO (Multi-User MIMO) over SU-MIMO?
- It increases the range of each transmission
- It allows the AP to transmit to multiple clients simultaneously (Correct answer)
- It reduces the number of antennas required
- It eliminates the need for beamforming
Correct answer: It allows the AP to transmit to multiple clients simultaneously
MU-MIMO allows an AP to transmit to multiple clients at the same time using spatial multiplexing, increasing total network efficiency.
Question 7: In WPA3-Enterprise, which security improvement over WPA2-Enterprise is mandatory?
- TKIP encryption
- 192-bit minimum security suite (CNSA) (Correct answer)
- MAC address filtering
- WPS enrollment
Correct answer: 192-bit minimum security suite (CNSA)
WPA3-Enterprise mandates a 192-bit security suite aligned with CNSA (Commercial National Security Algorithm) for higher-assurance networks.
ACA Wireless Technologies 3
What is the function of the Aruba AP's 'air monitor' mode?