CompTIA Network+ (N10-008) — Question 805

A network engineer is investigating reports of poor network performance. Upon reviewing a report, the engineer finds hundreds of CRC errors on an interface.
Which of the following is the MOST likely cause of these errors?

Answer options

• A. A bad wire on the Cat 5e cable
• B. The wrong VLAN assignment to the switchport
• C. A misconfigured QoS setting on the router
• D. Both sides of the switch trunk set to full duplex

Correct answer: A

Explanation

The presence of CRC errors typically indicates physical layer issues, most commonly caused by faulty cabling. A bad wire in the Cat 5e cable can introduce noise and interference, leading to these errors. The other options pertain to higher layer configurations that are less likely to cause CRC errors.