CompTIA Network+ (N10-009)Network TroubleshootingMedium
A technician is troubleshooting a server that is intermittently losing network connectivity. The server is connected via a Cat 6 cable to a network switch. During inspection, the technician notices the cable runs parallel to a large, unshielded power conduit for approximately 15 meters. Which of the following is the MOST likely cause of the intermittent connectivity?
- AExcessive EMI/RFI.
- BIncorrect IP address configuration.
- CDuplex mismatch.
- DNear-end crosstalk (NEXT).
Show answer & explanationAnswer & explanation
Correct answer: A. Excessive EMI/RFI.
Running an unshielded network cable parallel to a large power conduit creates a strong potential for Electromagnetic Interference (EMI) or Radio Frequency Interference (RFI). This interference can corrupt data signals, leading to intermittent connectivity issues, packet loss, and performance degradation.
Why the other options are wrong
- B. Incorrect IP configuration would cause consistent connectivity loss, not intermittent issues.
- C. Duplex mismatch typically results in severe, persistent performance issues, not intermittent connectivity.
- D. NEXT is crosstalk within the cable itself, typically due to improper termination, and while it degrades performance, it's less likely to cause intermittent loss of connectivity than external EMI from a power conduit.
Electromagnetic Interference (EMI)
Disruption of operation of an electronic device when it is in the vicinity of an electromagnetic field (EM field) in the radio frequency (RF) spectrum that is caused by another electronic device.
- Can cause intermittent connectivity, data corruption, and signal degradation.
- Sources include power lines, fluorescent lights, motors, and radio transmitters.
- Mitigated by shielding cables, proper grounding, and physical separation.
Memory trick: When the signal 'flickers', think of outside 'noise'.