Network forensics is an evolution of typical digital forensics, where evidence is gathered and analyzed from network traffic. This book will help security and network forensics professionals, as well as network administrators, understand the challenges faced by organizations and individuals investigating network-based criminal cases. The authors not only present various tools used to examine network traffic but also introduce different investigative methodologies. With the explosive growth in Internet-based technology (e.g., social networks, cloud computing, telecommuting), computer and network forensics investigators are among the fastest areas of growth. Specifically, in the area of cybercrime and digital forensics, the federal government is conducting a talent search for 10K qualified specialists. Key network forensics skills and tools are discussed-for example, capturing network traffic, using Snort for network-based forensics, using NetWitness Investigator for network traffic analysis, and deciphering TCP/IP. The current and future states of network forensics analysis tools are addressed. The admissibility of network-based traffic is covered as well as the typical life cycle of a network forensics investigation.