This authoritative guide explores computer network infrastructures and protocol design security flaws, as well as discussing current security solutions and best practices, in both fixed and mobile computer networks. It broadly surveys thought-provoking security issues and discusses and raises questions about the impact of these new technologies and protocols, with particular emphasis on the rapid growth and skyrocketing interests and use in mobile technologies. It explores the security threats and vulnerabilities in the current network infrastructure and protocols and outlines current security efforts. It provides support materials for lecturers and students such as PowerPoint slides, syllabus suggestions, solutions, instructor manual and student laboratory materials. This text/reference is an invluable instructional and rsearch tool for undergraduates in computer and information security - it will also be a rich resource for practitioners, and professionals.