For this module most of the tools we need are already on the computer. The TCP/IP stack installs automatically with the OS. In this day and age, it is inconceivable not to be networked. It wasn't always like that ;-).

For catching a glimpse of PDU's, explanation follows much later, and their traffic around your computer and network, we need a so called sniffer. Official name for software like that Network Protocol Analyzer. A program that uitilizes some capabilities of your network interface allowing it to read network traffic, including traffic not intended for your computer, and making it available for display. We need the wireshark-program.