A network technician notices that a switch port connected to a user's computer is showing a high number of CRC errors and late collisions. The link is operating at 100 Mbps, full duplex according to the switch. Which of the following is the most likely cause of these errors?

Cable length exceeds 100 meters

Excessive cable length can cause signal degradation and errors, but late collisions are a strong indicator of duplex mismatch, not cable length.

Faulty switch port

A faulty port would likely show link flapping or high error rates on all traffic, but late collisions specifically point to duplex mismatch.

Electromagnetic interference

EMI could cause CRC errors but is less likely to cause late collisions, which are timing-related and characteristic of duplex problems.

What does this N10-009 question test?

Read the scenario before looking for a memorised answer.

What is the correct answer to this question?

The correct answer is: Duplex mismatch — CRC errors and late collisions often indicate a duplex mismatch. Despite the switch reporting full duplex, the computer may have failed autonegotiation and be operating at half duplex. In half duplex, the computer can transmit while the switch is already sending, causing collisions and CRC errors. Cable length beyond 100 meters can cause errors but typically results in intermittent connectivity or excessive attenuation. A faulty switch port would likely show other symptoms. EMI can cause errors but is less specific than duplex mismatch.

What should I do if I get this N10-009 question wrong?

Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.