Requiring system accessibility via the Internet poses several problems for system administrators. One problem is allowing access by authorized users with the least amount of complexity on the client computer while keeping the system and its services safe from intruders. Common services that may be provided include web server, File Transfer Protocol (FTP) server, and Secure Shell (SSH) server. Each of these services can require different methods of security to ensure only authorized users have access.

Back in my system administration days, which were pre-broadband I set up a home network with my link to the outside world being through an ISDN router. One of my co-workers came over to the house and I showed him my network, which consisted of Unix machines (Solaris, HP-UX, Linux) and Windows (NT & 98), and a Mac, to which he remarked, “You have all the cool toys, Frankie!”