As Rails developers we depend on the network. But if you're new to web development, it's probably a mystery. That's a problem. Knowing how the network works is critical for fixing certain types of bugs and for diagnosing performance issues. In this talk, we'll follow the lives of a TCP and an HTTP request, marvel as they pass through your browse, OS, router, web server and app serve. Finally, we'll discuss how this knowledge is used to fix common bugs and increase app performance.