Network troubleshooting
Network troubleshooting is a vast subject. However, most of the time, experts use the same tools that are available to every novice and those tools are not hard to learn to use at a basic level. The main difference between a novice and an expert is how well they can interpret their outputs and choose the correct options.
Using ping
The name of the ping utility comes from the sound of sonar—a device that uses sound pulses to discover objects underwater. That command metaphorically probes a remote host by sending an ICMP packet and listening for a reply. The sonar metaphor is a bit of a stretch because sound pulses are passively reflected, while the exchange of ICMP packets requires cooperation from a remote host.
Still, a host that runs a correctly implemented network stack should reply with an ICMP echo reply packet if it receives an echo request. At the most basic level, pinging a host tells you whether the host is online and whether there is...
