tcpdump is a network and packet analysis utility in linux/unix OSes for performing network and packet sniffing. In this tutorial, we will show you some important commands of tcpdump along with great examples to get you started with analysis of packets on your network.. This utility runs on the command line in linux/unix and a great alternative utility for Windows is known as Wireshack. It allows the user to display TCP/IP and other packets being transmitted or received over the network to which the computer is attached. Moreover, it is a free software to install and use. SO lets get started with the great examples to perform network and packet analysis using tcpdump