You recently purchased four laptops containing dual-band 802.11ac adapters. The laptops can connect to your 2.4 GHz network, but they cannot connect to the 5 GHz network. The laptops do not show the 5 GHz SSIDs, which are different than the 2.4 GHz SSIDs. Existing devices can connect to the 5 GHz SSIDs with no difficulty. What is the likely problem?

1. A. Interference from non-Wi-Fi sources
2. B. Faulty drivers
3. C. DoS attack
4. D. Interference from other WLANs

Correct Answer: D

You are reconfiguring an AP to use the short guard interval. How long will the new guard interval duration be after the change?

1. A. 400 ns
2. B. 10 ms
3. C. 800 ns
4. D. 104 ms

Correct Answer: A
Reference https://www.sonicwall.com/en-us/support/knowledge-base/170504672960493

What is always required to establish a high quality 2.4 GHz RF link at a distance of 3 miles (5 kilometers)?

1. A. Grid antennas at each endpoint
2. B. A Fresnel Zone that is at least 60% clear of obstructions
3. C. A minimum antenna gain of 11 dBi at both endpoints
4. D. Minimum output power level of 2 watts

Correct Answer: B

What 802.11 PHY uses available space in very low frequency ranges that is not in use at the time by broadcast video signals?

1. A. DMG
2. B. SIG
3. C. DSSS
4. D. TVHT

Correct Answer: C
https://www.cwnp.com/802-11ac-vht-just-the-facts/

In an 802.11 2.4 GHz system, what 22 MHz channels are considered non-overlapping?

1. A. 11 and 6
2. B. 7 and 11
3. C. 1 and 5
4. D. 2 and 8

Correct Answer: A