SSH (Secure Shell) is a TCP/IP-based solution to many network security and privacy concerns. It supports secure remote logins, secure file transfer between computers, and a unique "tunnelling" capability that adds encryption to otherwise insecure network applications. Best of all, SSH is free, with feature-filled commercial versions available as well. This text covers the Secure Shell in detail for both system administrators and end users. It demystifies the SSH man pages and includes thorough coverage of: SSH1, SSH2, OpenSSH, and F-Secure SSH for Unix, plus Windows and Macintosh products - the basics, the internals, and complex applications; configuring SSH servers and clients, both system-wide and per user, with recommended settings to maximize security; advanced key management using agents, agent forwarding, and forced commands; forwarding (tunnelling) of TCP and X11 applications in depth, even in the presence of firewalls and network address translation (NAT); undocumented behaviours of popular SSH implementations; installing and maintaining SSH systems; and troubleshooting a wide variety of common and not-so-common problems. Whether you're communicating on a small LAN or across the Internet, SSH can ship your data from "here" to "there" efficiently and securely. So throw away those insecure .rhosts and hosts.equiv files, move up to SSH, and make your network a safe place to live and work.