Linux networks are becoming more and more common, but security is often an overlooked issue. Unfortunately, in today's environment all networks are potential hacker targets, from top-secret military research networks to small home LANs. Linux Network Security focuses on securing Linux in a networked environment, where the security of the entire network needs to be considered rather than just isolated machines. It uses a mix of theory and practical techniques to teach administrators how to install and use security applications, as well as how the applications work and why they are necessary. Starting with the need for security and understanding the problem, the book teaches administrators about packet filtering (firewalling) with iptables, hardening services such as Apache, BIND, Sendmail, FTP, and MySQL to prevent attacks, network analysis, encryption, local security, DoS attacks, and rootkits. Auditing networks for potential vulnerabilities and creating secure passwords is also explored. This is the one book that really details how to secure a Linux network.