Common tools used to diagnose network problems.
Network troubleshooting is a systematic process of identifying, diagnosing, and resolving problems in a computer network. A variety of tools are available to assist with this process. Some of the most fundamental are command-line utilities. `ping` is used to test the reachability of a host on an IP network by sending ICMP echo request packets and waiting for a reply. It's the first tool to use to check basic connectivity. `traceroute` (or `tracert` on Windows) maps the path that a packet takes from the source to the destination, showing the IP address of each router (hop) along the way. This is useful for identifying where a connectivity problem might be occurring. `ipconfig` (Windows) or `ifconfig`/`ip` (Linux/macOS) is used to display the IP configuration of a network interface, including its IP address, subnet mask, and default gateway. `netstat` displays active network connections, routing tables, and interface statistics. For more in-depth analysis, a packet analyzer or 'sniffer' like Wireshark is indispensable. Wireshark captures network traffic in real time and displays the contents of each packet in a human-readable format. It allows you to see exactly what is happening on the network at a very detailed level, making it an incredibly powerful tool for diagnosing complex protocol issues, security problems, and performance bottlenecks.