Question

Difficulty: MediumWired and Wireless Network Issues

A field technician is troubleshooting a newly relocated workstation in a medical office that cannot access the internet or local file shares. The network administrator confirms that the switch port is enabled, but the network interface card (NIC) link light on the back of the workstation and the corresponding port LED on the patch panel remain completely unlit. Which of the following actions should the technician take FIRST?

  1. Inspect the Ethernet patch cable for damage and ensure it is securely connected to the wall jack and NIC.Answer
  2. B
    Execute command-line ping and traceroute utilities to locate where traffic is being dropped on the local network.
  3. C
    Reconfigure the local DNS server to issue a new dynamic IP address lease to the workstation host.
  4. D
    Install an unmanaged Layer 2 switch between the workstation and wall jack to route packets between subnets.

Answer

Inspect the Ethernet patch cable for damage and ensure it is securely connected to the wall jack and NIC.
When both the workstation NIC link light and switch port LED are unlit, there is a physical layer (Layer 1) disconnect. According to the standard bottom-up troubleshooting model, verifying cable seating, checking for physical cable damage, or swapping out the patch cable must be performed first to establish electrical/optical link before testing software layers.

Step-by-Step Solution

1
Analyze the physical status indicators on the workstation NIC and patch panel.
Unlit LEDs indicate a complete lack of Layer 1 (Physical layer) signal electrical or optical link.
According to the CompTIA troubleshooting methodology, physical layer issues must be resolved before higher-layer testing can yield results.
2
Identify the immediate corrective action for Layer 1 link failure.
Checking for unplugged cables, pin damage, or broken RJ-45 locking tabs directly targets physical connectivity.
Replacing or reseating the patch cable verifies or restores physical connection integrity.

Key Concept

Physical Layer Network Troubleshooting and Link Light Verification
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