220-1101 Question 170
Single answerWi-Fi analyzerA technician is troubleshooting intermittent wireless connectivity in a small office. Users report that connections drop and throughput is poor, especially around midday. The wireless router is operating on the 2.4 GHz band. The technician uses a Wi-Fi analyzer and finds that the company SSID is on channel 6, while several nearby networks have strong signals on channels 4, 5, 6, 7, and 8. Which action should the technician take FIRST to reduce interference and improve stability?
- A
Change the wireless network to channel 1 or channel 11 after checking which has less congestion
- B
Increase the router transmit power to maximum so the company signal overpowers nearby networks
- C
Enable MAC filtering so unauthorized nearby devices cannot connect and cause interference
- D
Switch the SSID to a hidden network so neighboring Wi-Fi analyzers cannot detect it
Show answer and explanation
Correct answer: A
Explanation
A Wi-Fi analyzer helps technicians visualize nearby wireless networks, signal strength, and channel usage. In a congested 2.4 GHz environment, interference commonly comes from overlapping or heavily utilized channels. Best practice is to place the access point on the least congested non-overlapping channel, typically 1, 6, or 11 in regions where those channels apply. Since channel 6 is crowded in this scenario, the technician should move to channel 1 or 11 after verifying which is cleaner in the analyzer. This aligns with common wireless troubleshooting guidance from enterprise WLAN design practices and vendor documentation, which recommend minimizing adjacent-channel overlap and selecting the least congested non-overlapping channel before attempting more invasive changes.
- A. Correct.
Correct. On the 2.4 GHz band, channels 1, 6, and 11 are the commonly used non-overlapping channels in many regions. If channel 6 is crowded and overlapping networks are present on adjacent channels 4, 5, 7, and 8, moving to channel 1 or 11 based on analyzer results is the best first step. A Wi-Fi analyzer is specifically used to identify channel utilization and neighboring signal overlap so the technician can choose a less congested channel.
- B. Incorrect.
Incorrect. Raising transmit power does not solve co-channel or adjacent-channel interference and can make the environment worse by increasing contention and causing excessive signal bleed. This is a common misconception because a stronger signal does not eliminate interference from other access points using overlapping spectrum.
- C. Incorrect.
Incorrect. MAC filtering is a basic access control measure, not a tool for reducing RF interference. Nearby networks using the same or overlapping channels will still create contention and interference even if their clients cannot join the company's wireless network.
- D. Incorrect.
Incorrect. Hiding the SSID only stops casual broadcast of the network name; it does not prevent detection by Wi-Fi analyzers and does not reduce radio-frequency interference. The problem described is channel congestion, which requires channel planning rather than SSID obfuscation.