220-1101 Question 166
Single answerWireless local area network (WLAN)A small office recently replaced its wireless router. Since the change, several older barcode scanners in the warehouse can see the SSID but fail to connect, while newer laptops and phones connect without issue. The wireless network is configured for WPA2-Personal, and the password has been verified. The technician notices the new router is set to 802.11ax mode on the 5 GHz band only. Which of the following is the MOST likely reason the barcode scanners cannot connect?
- A
The barcode scanners do not support the 5 GHz band and require 2.4 GHz wireless
- B
WPA2-Personal is incompatible with devices that do not support 802.11ax
- C
The SSID must be hidden for legacy wireless devices to authenticate properly
- D
The router must be configured to use WPA3-Personal for mixed-device environments
Show answer and explanation
Correct answer: A
Explanation
This scenario tests practical WLAN troubleshooting. The strongest clue is that older barcode scanners fail while newer laptops and phones work, and the new router is configured for 5 GHz only. Many legacy business devices support only 2.4 GHz wireless, commonly using 802.11b/g/n radios. In real-world support, technicians frequently resolve this by enabling 2.4 GHz service, verifying compatible security settings such as WPA2-Personal, and avoiding configurations that require newer hardware features. CompTIA A+ Core 1 expects candidates to understand WLAN standards, frequency bands, and compatibility issues. Industry best practice from wireless vendors and enterprise deployment guidance also recognizes that 2.4 GHz remains necessary for many older or specialized devices, even when newer client devices prefer 5 GHz for performance.
- A. Correct.
Correct. Many older wireless devices, including barcode scanners, support only 2.4 GHz 802.11b/g/n wireless and cannot join a WLAN that is operating only on 5 GHz. A device may still show inconsistent behavior in discovery depending on its wireless capabilities and how the issue is reported, but in practice the key problem is that older devices commonly require 2.4 GHz support. Enabling a 2.4 GHz SSID or mixed-band configuration is a common fix in real deployments.
- B. Incorrect.
Incorrect. WPA2-Personal is not dependent on 802.11ax support. A client does not need to support Wi-Fi 6 specifically in order to use WPA2-Personal. Wireless security standards and 802.11 PHY standards are related but separate. An older device can often connect to a modern access point if the AP is configured with compatible bands, channels, and legacy support.
- C. Incorrect.
Incorrect. Hiding an SSID does not help legacy devices authenticate. In fact, hidden SSIDs often create additional connection and management issues and are not considered a meaningful security improvement. A device's ability to authenticate depends on compatible wireless standards, frequency support, and security settings, not whether the SSID is broadcast.
- D. Incorrect.
Incorrect. WPA3-Personal would make compatibility worse, not better, for many older devices. Legacy scanners often lack WPA3 support. For mixed environments, WPA2-Personal or a WPA2/WPA3 transition mode is more practical when supported, but WPA3 is not the solution to a 5 GHz-only compatibility problem.