Chapter 4 - Using Ethereal

Abstract

Ethereal is an invaluable tool for providing insight into what is really happening on the network. This kind of insight is useful when implementing protocols, debugging network applications, testing networks, or trying to debug live networks. In almost any situation that involves interaction with the network at a technical level one can enhance the understanding of the problem by using Ethereal to see what is really going on. Ethereal is also an excellent pedagogical aid. Being able to see and analyze actual network traffic is extremely instructive. This chapter covers a discussion about the main components of the Ethereal Graphical User Interface (GUI).These parts are the Main Window and it's subcomponents the Menu Bar, Tool Bar, Summary Window, Protocol Tree Window, Data View Window, Filter Bar, and Information field. The chapter covers use of the context-sensitive pop-up windows available in the Summary Window, Protocol Tree Window, and Data View Window, and explains various dialog boxes that are launched by the menus and toolbars. It discusses how to perform basic tasks in Ethereal, such as, capturing network traffic, loading and saving capture files, performing basic filtering, printing packets, and using some of the more involved tools provided by Ethereal. Examples have been provided to show step-by-step procedure how some of the less obvious areas of Ethereal work.