N10-009 Question 327
Single answerHardware tools: Toner, Cable tester, Taps, Wi-Fi analyzer, Visual fault locatorA network technician is troubleshooting a newly installed multimode fiber run between an access switch in a telecom closet and a distribution switch on another floor. The switch ports show no link light, and the patch cords and transceivers have already been swapped with known-good components. The technician needs a quick way to determine whether the problem is a break, severe bend, or mis-terminated strand somewhere along the fiber path without using a full OTDR. Which hardware tool is the BEST choice for this task?
- A
Visual fault locator
- B
Cable tester
- C
Toner and probe
- D
Wi-Fi analyzer
Show answer and explanation
Correct answer: A
Explanation
The best answer is the visual fault locator because the scenario is focused on physical-layer troubleshooting of a fiber-optic run and asks for a fast method to identify whether there is a break, severe bend, or termination problem without using a more advanced tool like an optical time-domain reflectometer (OTDR). A VFL is specifically designed for this purpose and is widely used by technicians for short-range fault isolation in fiber cabling. By contrast, a toner/probe is for copper cable tracing, and a Wi-Fi analyzer is for wireless troubleshooting. A generic cable tester may confirm whether a cable passes basic tests, but it typically does not provide the direct visual indication needed to pinpoint an obvious fiber fault location. This aligns with common fiber troubleshooting practices described in manufacturer documentation and structured cabling guidance, where VFLs are recommended for quick visual verification and basic fault location on fiber links.
- A. Correct.
Correct. A visual fault locator (VFL) injects visible light, typically a red laser, into a fiber strand so the technician can identify obvious breaks, sharp bends, and some termination issues by seeing where light escapes. It is commonly used for quick, short-range fiber troubleshooting when a full OTDR is not necessary.
- B. Incorrect.
Incorrect. A cable tester is useful for validating copper pinouts, continuity, opens, shorts, split pairs, and in some cases basic fiber continuity depending on the model, but it is not the best tool for visually locating the physical point of a bend, break, or bad termination along a fiber run. The scenario specifically asks for a quick way to find the likely fault location on fiber.
- C. Incorrect.
Incorrect. A toner and probe is used to identify and trace copper cable runs, typically unshielded twisted pair, by sending a tone that can be followed with a probe. It is not used to trace or diagnose faults inside a fiber-optic cable.
- D. Incorrect.
Incorrect. A Wi-Fi analyzer is used to assess wireless conditions such as channel utilization, signal strength, interference, and overlapping networks. It has no role in troubleshooting a physical fiber link between switches.