2. Conventions

This text was written in DocBook with vim. All formatting has been applied by xsltproc based on DocBook and LDP XSL stylesheets. Typeface formatting and display conventions are similar to most printed and electronically distributed technical documentation. A brief summary of these conventions follows below.

The interactive shell prompt will look like


for the root user and


for non-root users, although most of the operations we will be discussing will require root privileges.

Any commands to be entered by the user will always appear like

{ echo "Hi, I am exiting with a non-zero exit code."; exit 1 }

Output by any program will look something like this:

Hi, I am exiting with a non-zero exit code.

Where possible, an additional convention I have used is the suppression of all hostname lookup. DNS and other naming based schemes often confuse the novice and expert alike, particularly when the name resolver is slow or unreachable. Since the focus of this guide is IP layer networking, DNS names will be used only where absolutely unambiguous.