Book excerpt: Ethereal is the #2 most popular open source security tool used by system administrators and security professionals. This all new book builds on the success of Syngress' best-selling book Ethereal Packet Sniffing.Wireshark & Ethereal Network Protocol Analyzer Toolkit provides complete information and step-by-step Instructions for analyzing protocols and network traffic on Windows, Unix or Mac OS X networks. First, readers will learn about the types of sniffers available today and see the benefits of using Ethereal. Readers will then learn to install Ethereal in multiple environments including Windows, Unix and Mac OS X as well as building Ethereal from source and will also be guided through Ethereal's graphical user interface. The following sections will teach readers to use command-line options of Ethereal as well as using Tethereal to capture live packets from the wire or to read saved capture files. This section also details how to import and export files between Ethereal and WinDump, Snort, Snoop, Microsoft Network Monitor, and EtherPeek. The book then teaches the reader to master advanced tasks such as creating sub-trees, displaying bitfields in a graphical view, tracking requests and reply packet pairs as well as exclusive coverage of MATE, Ethereal's brand new configurable upper level analysis engine. The final section to the book teaches readers to enable Ethereal to read new Data sources, program their own protocol dissectors, and to create and customize Ethereal reports. - Ethereal is the #2 most popular open source security tool, according to a recent study conducted by insecure.org - Syngress' first Ethereal book has consistently been one of the best selling security books for the past 2 years