Network troubleshooting
⏱ ~3-min readAceMark Guide
What this topic is really about
Late collisions are a classic symptom of a duplex mismatch; both ends must agree, typically by both auto-negotiating or both hard-set to full duplex. Mismatched settings (one full, one half) cause the errors, and duplex cannot be disabled on Ethernet.
traceroute (tracert on Windows) shows the round-trip time to each hop along the path, helping pinpoint where latency or loss begins. nslookup queries DNS, arp -a shows MAC-to-IP mappings, and netstat lists connections and ports.
See the mechanism
A cable tester verifies continuity, opens, shorts, and that wires terminate to the correct pins on each end. A diagram for this topic isn't available yet — the worked example below walks the same reasoning step by step.
An exam-style question, fully explained
Which tool tests a copper Ethernet cable for opens, shorts, and incorrect pinouts?
- Identify what the question tests: Which tool tests a copper Ethernet cable for opens, shorts, and incorrect pinouts.
- A cable tester verifies continuity, opens, shorts, and that wires terminate to the correct pins on each end.
- A tone generator helps trace cables.
- Loopback plugs verify a single port works.
- Spectrum analysers are for wireless.
Traps the examiner sets
- Read each option carefully — distractors on Network troubleshooting are designed to look plausible.
- Re-check the exact wording of the question stem before committing to an answer.
- Watch the qualifiers ("always", "only", "except") that flip a correct-looking option.
Test your recall
Answer each from memory — you'll see instantly whether you're right and why.
Run a focused 10-question mini-mock on Network troubleshooting and see it stick.
Practice more of this topic →