220-1101 Question 130
Single answerPatch panelA technician is troubleshooting a user's network connection in a small office. The wall jack at the user's desk is connected through horizontal cabling to a patch panel in the wiring closet. The switch port shows no link light for that office run, but the switch and the user's PC NIC are known to be working. To restore connectivity quickly without re-terminating permanent cabling, which action should the technician take FIRST?
- A
Replace the horizontal cable inside the wall with a crossover cable
- B
Move the user's PC to a different VLAN on the switch
- C
Test and replace the patch cable between the patch panel port and the switch port
- D
Punch down the user's cable directly into the switch to bypass the patch panel
Show answer and explanation
Correct answer: C
Explanation
The best first action is to test or replace the patch cable between the patch panel and the switch. In structured cabling, the permanent link runs from the work-area outlet to the patch panel, and short patch cords are used to connect the patch panel to network equipment. Because patch cords are easy to swap and commonly fail from wear, they should be checked before more invasive steps such as re-terminating cabling. This aligns with standard troubleshooting methodology: verify physical connectivity first and start with the least disruptive, most likely fault. Industry structured cabling practices reflected in TIA/EIA-568 guidance distinguish between permanent cabling and patch cords specifically to support easier maintenance and troubleshooting.
- A. Incorrect.
Incorrect. The in-wall horizontal cable is part of the permanent link and is not replaced with a crossover cable. Crossover cables were historically used for direct device-to-device connections, not for fixed structured cabling runs through a patch panel. Replacing in-wall cabling is also not the quickest first step when the goal is to restore service without re-terminating permanent cabling.
- B. Incorrect.
Incorrect. A VLAN mismatch can prevent network access at Layer 2 or Layer 3, but it does not typically explain a complete lack of link light on the switch port for an otherwise known-good NIC and switch. No link light points first to a physical-layer issue, such as a bad patch cable, bad port, or bad termination.
- C. Correct.
Correct. The patch cable connecting the patch panel to the switch is part of the channel and is a common failure point. Best practice is to troubleshoot from the simplest and most easily replaceable physical components first. Swapping or testing the patch cable is fast, non-destructive, and consistent with structured cabling design, where the patch panel provides a convenient cross-connect point between permanent building cabling and active equipment.
- D. Incorrect.
Incorrect. Directly punching station cabling into a switch is not standard practice and defeats the purpose of structured cabling. Patch panels are used to terminate permanent horizontal cabling cleanly and safely, allowing moves, adds, and changes using short patch cords instead of disturbing building cabling. Bypassing the patch panel can damage equipment or cabling management and is not the appropriate first step.