220-1101 Question 415
Single answerPhysical cabling issuesA technician is troubleshooting a desktop that intermittently loses its network connection after users move the PC to clean behind the desk. The link light on the NIC goes out when the cable is bumped near the wall jack, and a cable tester shows occasional opens on one pair. Which action is the BEST next step to resolve the physical cabling issue?
- A
Replace the patch cable between the PC and the wall jack
- B
Reboot the desktop and update the NIC driver
- C
Change the speed and duplex settings on the switch port
- D
Assign a static IP address to the desktop
Show answer and explanation
Correct answer: A
Explanation
This scenario is a classic Layer 1 troubleshooting problem involving physical cabling. The strongest clues are that the NIC link light goes out when the cable is bumped and that a cable tester reports intermittent opens on a pair. In structured cabling environments, the best practice is to start with the simplest and most replaceable component: the patch cable from the device to the wall jack. Patch cables are designed to be replaceable and are more likely to fail than in-wall horizontal cabling. CompTIA A+ Core 1 objectives emphasize identifying physical cable faults such as damaged connectors, shorts, opens, and intermittent connectivity due to cable damage. Standard troubleshooting methodology also supports beginning with the most likely and least disruptive fix before escalating to jack retermination or horizontal cable replacement.
- A. Correct.
Correct. The symptoms point to a physical layer problem on the cable run the user is interacting with most directly. If the link drops when the cable is bumped near the jack and a tester reports intermittent opens, the most practical first fix is to replace the patch cable. Patch cords are common failure points because they are frequently bent, stepped on, or strained during cleaning and desk movement.
- B. Incorrect.
Incorrect. Rebooting or updating the NIC driver addresses software or driver-related connectivity issues, but it would not explain why the link light goes out when the cable is physically disturbed or why a cable tester reports intermittent opens.
- C. Incorrect.
Incorrect. Speed and duplex mismatches can cause poor performance, collisions, or intermittent communication, but they do not typically cause the physical link light to drop when the cable is moved. This option targets a configuration issue rather than a damaged cable or termination.
- D. Incorrect.
Incorrect. IP addressing problems can prevent communication on the network, but they do not cause the NIC link light to turn off or produce open-pair results on a cable tester. This distractor reflects a common misconception of jumping to Layer 3 before resolving a clear Layer 1 fault.