Which sequence best describes a basic OSI-model troubleshooting approach using common network commands?

• A. traceroute, ping, nslookup, ifconfig, netstat.
• B. nslookup, traceroute, ping, netstat, ifconfig.
• C. ping to verify basic connectivity, nslookup for DNS, traceroute for path, and netstat for ports/listening services.
• D. ifconfig, netstat, ping, traceroute, nslookup.

Answer: (C)

The main idea is to troubleshoot by moving from basic connectivity to service verification, aligning with the layers from simple reachability to name resolution, path discovery, and then service status. Starting with a basic ping confirms whether the host can be reached at all, which tells you if the network layer is functioning between the two endpoints. If ping succeeds, you then test DNS with a lookup to ensure names resolve to the correct IPs, since many applications rely on proper name resolution to reach a service. Next, traceroute reveals the path packets take to the destination and can show where routing issues or bottlenecks occur along the route. Finally, checking with netstat tells you which ports are open and which services are listening, confirming that the desired application is actually available to receive traffic. This sequence keeps the investigation focused and efficient, progressively narrowing down where a problem could lie.

Starting with path discovery or DNS before basic connectivity can lead to confusion if the host isn’t reachable at all, and introducing interface configuration steps early isn’t part of this standard top-down diagnostic flow.