Tcpdump

tcpdump is a data-network packet analyzer computer program that runs under a command line interface. It allows the user to display TCP/IP and other packets being transmitted or received over a network to which the computer is attached. Distributed under the BSD license, tcpdump is free software.

Tcpdump works on most Unix-likeoperating systems: Linux (including Android and embedded distribution such as OpenWrt), Solaris, FreeBSD, DragonFly BSD, NetBSD, OpenBSD, macOS, HP-UX 11i, and AIX. In those systems, tcpdump uses the libpcap library to capture packets. The port of tcpdump for Windows is called WinDump; it uses WinPcap, the Windows version of libpcap.