This book is written to comply with the comprehensive national cyber security initiative #8: cybersecurity education, cyber network and will serve as a detailed, hands-on guide for anyone who wants to enter the hands-on security profession, including cybersecurity testing, it testing/development, and system/network administration. it will also serve as the text for a cybersecurity course at 2 and 4 year colleges and vocational cybersecurity education. the book is also a useful reference for working cybersecurity professionals for techniques such as advanced filtering with wireshark and tcpdump, command line scripting, network penetration, tool customization, network administration, and log analysis. this book covers basic network administration skills that everyone needs through to advanced command line scripting, tool customization, and log analysis skills that are very useful in every shop, but few professionals have.