CompTIA Network+ (N10-009)Network TroubleshootingEasy

A network technician is investigating reports of intermittent network connectivity and slow speeds for users connected to a specific wireless access point. The access point is located near a microwave oven in a break room. What is the MOST likely cause of these issues?

  1. AInsufficient power over Ethernet (PoE) budget.
  2. BIncorrect VLAN tagging on the access point's port.
  3. CElectromagnetic Interference (EMI) from the microwave oven.
  4. DOutdated firmware on the wireless access point.
Show answer & explanation

Correct answer: C. Electromagnetic Interference (EMI) from the microwave oven.

Microwave ovens operate in the 2.4 GHz frequency range, which directly interferes with common Wi-Fi bands. This interference can cause significant signal degradation, leading to intermittent connectivity and slow speeds.

Why the other options are wrong

  • A. Insufficient PoE budget would likely cause the access point to not power on or reboot, not intermittent connectivity.
  • B. Incorrect VLAN tagging would typically prevent any connectivity, not cause intermittent issues or slow speeds.
  • D. Outdated firmware can cause various issues, but EMI is a more direct and common cause when located near a strong interference source like a microwave.

Electromagnetic Interference (EMI)

Disruption that affects an electrical circuit due to electromagnetic induction or electromagnetic radiation emitted from an external source.

  • Can be caused by motors, fluorescent lights, microwave ovens, and other electrical devices.
  • Degrades signal quality on copper cables and wireless links.
  • Mitigated by shielding, proper grounding, and physical separation.

Memory trick: Radio waves clash, Wi-Fi crashes.

More Network Troubleshooting questions