Practise narrating network troubleshooting steps, describing connectivity issues, and communicating diagnoses in English.
0 / 5 completed
1 / 5
When troubleshooting a connectivity issue, which approach follows the OSI model correctly?
Bottom-up troubleshooting: first confirm physical connectivity (Layer 1), then data link (Layer 2, ARP), network (Layer 3, routing), transport (Layer 4, ports), before investigating application issues.
2 / 5
The command 'traceroute' (or tracert) is used to:
Traceroute shows each hop (router) between source and destination with round-trip times — essential for identifying where packet loss or high latency occurs.
3 / 5
Which phrase correctly describes a packet loss issue?
Precise network issue descriptions include: the metric (15% packet loss), the location (edge router to ISP handoff), and the observed effect (TCP retransmissions) for faster diagnosis.
4 / 5
MTU (Maximum Transmission Unit) mismatch causes:
MTU mismatch typically causes large packets (e.g., GRE-tunnelled) to be dropped silently — symptoms include small requests working but large file transfers or VPN traffic failing.
5 / 5
When a network engineer says 'the interface is flapping', they mean:
Interface flapping (rapid up/down cycling) destabilises routing tables — every flap triggers route withdrawals and re-advertisements, causing network convergence issues.