Advanced.Linux.Networking..Roderick.Smith [Electronic resources] نسخه متنی

Conventions
Used in This Book

In discussing computers and software, it's
easy to become confused because it's not always clear when a word has its usual
meaning and when it refers to a computer, file, program, command, or what have
you. For this reason, this book uses certain typographic conventions to help
clarify matters. Specifically:

The bulk of the text appears in a normal,
proportionally-spaced font, like this.

Italicized text indicates an important term that's appearing for the first time in
a chapter. It's also occasionally used for emphasis.

Monospaced text indicates a filename, computer name, the syntax used by a command,
the contents of configuration files, or the output of commands typed at a
command prompt. Sometimes program names appear in this way, when these names
are really the software's filename.

Italicized
monospaced text indicates a
variableinformation that may differ on your system. For instance, instructions
might say to create a file whose name is unimportant or system-specific. The
instructions might then refer to this file as file.txt .

Bold monospaced
text indicates information you should type
exactly at a command prompt. When isolated on a line of its own, it's usually
preceded by a monospaced but non-bold prompt, such as # , which the
computer generates. This type of text may also be italicized, to indicate that
what you type will depend upon your configuration or the results you intend to
achieve.

When a command you type appears on a line of
its own, the command is preceded by a command prompt. A pound sign ( # ) indicates a
root command prompt. Such commands are usually entered by root, not by
ordinary users (although there are exceptions to this rule). If the command
prompt is a dollar sign ( $ ), ordinary users may, and often do, enter the command. Some
unusually long commands use line continuation charactersbackslashes ( \ )at the ends
of all their lines but the first. You can type such commands exactly as they
appear, including the backslashes, or you can omit the backslashes and type
these commands entirely on one line. The backslashes exist just so that the
command can be typeset in a reasonable font size.

This book also uses a number of special text
elements that apply to entire paragraphs or larger segments of text. These
elements are intended to highlight important or peripheral information. They
are:

NOTE

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A Note is not critical to the main discussion, but the information it contains is interesting or may be helpful in certain circumstances. For instance, a Note might point out how a feature differed in previous versions of a program.

TIP

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A Tip contains information that can help you achieve a goal in a non-obvious way, or that can point you to uses of a system or software that might not have occurred to you.

WARNING

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A Warning describes a potential pitfall or danger. Warnings include software that could damage your system if used incorrectly, the potential to run afoul of ISP policies that forbid certain behaviors, and configurations that might leave your system vulnerable to outside intruders.

In discussing networks, it's often necessary
to give specific IP addresses as examples. In most cases, I've used IP
addresses from the ranges reserved for private networks
(192.168.0.0192.168.255.255, 172.16.0.0172.31.255.255, and
10.0.0.010.255.255.255) even for systems that would normally be on the Internet
at large. I've done this to avoid potential confusion or inadvertent offense
that might occur if I were to pick random legitimate IP addresses.