tcpdump
tcpdump is a command-line packet analyzer tool that captures and displays network traffic in real-time or from saved files. It allows users to monitor, filter, and analyze packets transmitted over a network interface, supporting various protocols like TCP, UDP, and ICMP. It is widely used for network troubleshooting, security analysis, and debugging network applications.
Developers should learn tcpdump when they need to diagnose network issues, such as connection failures, latency problems, or security breaches, by inspecting raw packet data. It is essential for roles involving network programming, system administration, or cybersecurity, as it provides low-level insights into network behavior that higher-level tools might miss. Use cases include debugging API calls, analyzing protocol implementations, and monitoring for suspicious network activity.