The protocol wars are over and TCP/IP won. TCP/IP is now universally recognized as the pre-eminent communications protocol for linking together diverse computer systems. The importance of interoperable data communications and global computer networks is no longer debated. But that was not always the case. When I wrote the first edition of this book, IPX was far and away the leading PC communications protocol. Microsoft did not bundle communications protocols in their operating system. Corporate networks were so dependent on SNA that many corporate network administrators had not even heard of TCP/IP. Even UNIX, the mother of TCP/IP, nursed a large number of pure UUCP networks. Back then I felt compelled to tout the importance of TCP/IP by pointing out that it was used on thousands of networks and hundreds of thousands of computers. How times have changed! Today we count the hosts and users connected to the Internet in the tens of millions. And the Internet is only the tip of the TCP/IP iceberg. The largest market for TCP/IP is in the corporate 'intranet.' An intranet is a private TCP/IP network used to disseminate information within the enterprise. The competing network technologies have shrunk to niche markets where they fill special needs - while TCP/IP has grown to be the communications software that links the world.
The acceptance of TCP/IP as a worldwide standard and the size of its global user base are not the only things that have changed. In 1991 I lamented the lack of adequate documentation. At the time it was difficult for a network administrator to find the information he or she needed to do the job. Since that time there has been an explosion of books about TCP/IP and the Internet. However, there are still too few books that concentrate on what a system administrator really needs to know about TCP/IP administration and too many books that try to tell you how to surf the Web. In this book I strive to focus on TCP/IP and UNIX, and not to be distracted by the phenomenon of the Internet.