Some last comments

Before proceeding to read the rest of this book, it should be noted that the text assumes that certain files are placed in certain directories. Where they have been specified, the conventions we adopt here for locating these files are those of the Red Hat Linux distribution. If you are using a distribution of Linux (or some other operating system) that chooses to distribute these files in a different way, you should be careful when copying examples directly from the text.
At this part of our book, all software-listed on chapter 10 through chapter 21 is optional and depends on what you want to install or do on your server, (e.g., What kind of tasks will your server do, and for which part of your network Intranet/Internet?) In other parts it may be important for you to replace the Telnet program with SSH for secure remote administration. Another interesting program is Tripwire that aids system administrators and users in monitoring a designated set of files for any changes.