In today's online, connected world where computers outsell TVs and e-commerce sales surpass those of "brick-and-mortar" stores, secure network environments are a necessity. Weaknesses within networks have led to the rapid growth of identity theft and computer virus outbreaks, so the demand for skilled and aspiring system administrators who can protect networks is growing. If you are tasked with protecting your networks from these threats, or are studying security, Introduction to Network Security will help you increase your understanding of potential threats, learn how to apply practical mitigation options, and react to attacks quickly. The book teaches you the skills and knowledge you need to design, develop, implement, analyze, and maintain networks and network protocols. It explains how these systems currently operate and the limitations that lead to security weaknesses. All of the fundamental issues needed to understand network security, including the definition of security terms, security ethics, the OSI network model, and cryptography for networks are covered in detail. The book focuses on the seven layers in the OSI network model by describing each overall layer, its security role, common vulnerabilities, and mitigation techniques. The discussion of each layer is followed by explicit examples of common protocols within the layer and their respective security issues. The last part of the book explores the common risks for secure network design and development, including the impact of modularity on security and a summary of the general security issues. If you are new to network security, a general IT administrator, or a student, this is a must-have a resource to help ensure that you have the skills and knowledge required to protect your networks!