220-1101 Question 454
Single answerIntermittent internet connectivityA user reports that their laptop loses internet access several times each day while working from a conference room. The Wi-Fi icon remains connected to the company SSID, but web pages stop loading for 30 to 60 seconds before working again. Other users in nearby offices are not reporting the issue. You verify that the problem occurs only in the conference room and only on wireless connections. Which of the following is the MOST likely cause?
- A
RF interference from nearby devices affecting the wireless signal
- B
A failed DNS server on the corporate network
- C
An incorrect default gateway configured on the laptop
- D
A damaged Ethernet patch cable between the switch and router
Show answer and explanation
Correct answer: A
Explanation
The best answer is RF interference from nearby devices. In A+ Core 1 troubleshooting, intermittent internet connectivity that occurs only in a specific physical area and only over Wi-Fi usually points to wireless signal problems such as interference, low signal strength, channel overlap, or obstacles. Best practice is to compare behavior in other locations, verify whether other users are affected, and isolate whether the issue is tied to wireless versus wired access. CompTIA A+ objectives emphasize identifying common network problems and wireless issues, including interference sources and environmental factors. In a real environment, the technician would next confirm signal strength, inspect access point placement, check for overlapping channels, and look for nearby devices operating in the 2.4 GHz or 5 GHz bands.
- A. Correct.
Correct. Intermittent connectivity in one specific area while the laptop still shows as connected to Wi-Fi strongly suggests a wireless quality issue rather than a total network outage. Conference rooms often contain projectors, wireless presentation systems, Bluetooth devices, microwaves in nearby break areas, or other electronics that can introduce radio frequency interference. This can cause short drops in usable throughput even though the client remains associated with the access point.
- B. Incorrect.
Incorrect. A failed DNS server would typically affect name resolution for many users, not just one user in one room. In addition, DNS issues usually cause symptoms such as being unable to reach websites by name while connectivity to IP addresses may still work. The scenario points to a location-specific wireless problem instead.
- C. Incorrect.
Incorrect. An incorrect default gateway would usually prevent reliable access to resources outside the local subnet on a consistent basis, not cause brief intermittent outages only in one conference room. Because the issue appears only in a specific location on wireless, a local RF or signal-quality problem is more likely than an IP configuration problem.
- D. Incorrect.
Incorrect. A damaged Ethernet cable between the switch and router would likely affect multiple users and possibly an entire segment of the network, not just one laptop in one conference room. The scenario also states that the problem occurs only on wireless connections, which makes a wired backbone cable less likely as the immediate cause.