SSH: From Secure Administration to Virtual Private Networking

Bottom Line
If you're still administering *NIX servers over the Internet using rsh or telnet, stop. OpenSSH is an inexpensive improvement well worth the minimal effort required to install and configure it. If you prefer to use a commercial product, there are several to choose from. SSL provides security for web-based administration; use SSH to protect command line and xterm-based administration.

If you're thinking about creating a VPN but your requirements are limited to just a few interactive protocols, consider SSH. Using SSH to provide secure Internet access to your home-office mail server isn't difficult, and performance probably isn't an issue. But if you're looking for high-speed tunneling between sites, SSH isn't for you: go with a network-layer VPN solution optimized for that purpose. And because SSH requires login accounts, it is best used in a trusted environment: I'd let my own users tunnel through my SSH server, but I'd think twice about allowing outsiders—or customers—to do so.