UNIX Versions

Most of the examples in this book are taken from Linux 2.0.0, which is a freely available UNIX-like operating system, and from Solaris 2.5.1, which is the Sun operating system based on System V UNIX. Fortunately, TCP/IP software is remarkably standard from system to system. Because the TCP/IP software is so uniform, the examples should be applicable to any Linux, System V, or BSD-based UNIX system. There are small variations in command output or command-line options, but these variations should not present a problem.

Some of the ancillary networking software is identified separately from the UNIX operating system by its own release number. Many such packages are discussed, and when appropriate are identified by their release numbers. The most important of these packages are:

BIND

Our discussion of the BIND software is based on version 4.9.5 running on a Slackware 96 Linux system. This version of BIND supports all of the standard resource records and there are relatively few differences between it and the current releases of BIND provided by computer vendors.

sendmail

Our discussion of sendmail is based on release 8.8.5. This version should be compatible with other releases of sendmail v8. However, sendmail has been changing rapidly in recent years.