Introduction to the GuideWelcome to the Red Hat Network 3.6 Reference Guide. The RHN Reference Guide will guide youthrough registering your system with Red Hat Network and using its many features.Since Red Hat Network offers a variety of service levels, from the most basic Update module to themost advanced Monitoring package, some content of this guide may be inapplicable to you. This isparticularly true of the RHN website, which displays selected categories, pages, and tabs dependingon the entitlement level of the account used to log in. Refer to Chapter 6 Red Hat Network Website todetermine what is available to you.Depending on which version of Red Hat Enterprise Linux you have installed, the Red Hat NetworkRegistration Client and the Red Hat Update Agent might be different than the ones described inthis manual as new features are added. Once you use Red Hat Network to update these applications,you can use the latest version of this manual.All versions of this manual are available in HTML and PDF formats athttp://www.redhat.com/docs/manuals/RHNetwork/.This version of the manual covers version 4.2.38 of the Red Hat Enterprise Linux 3 Red Hat UpdateAgent and versions 2.9.14 and 2.9.12 of the Red Hat Enterprise Linux 2.1 Red Hat Update Agentand Red Hat Network Registration Client, respectively.WarningSystems running Red Hat Enterprise Linux 2.1 will need to use the separate Red Hat NetworkRegistration Client before starting the Red Hat Update Agent. Refer to Chapter 5 Red Hat NetworkRegistration Client for instructions. Systems running Red Hat Enterprise Linux 3 can go directly tothe Red Hat Update Agent, which has registration functionality built in. Refer to Chapter 2 Red HatUpdate Agent for instructions.For an overview of Red Hat Network offerings, please review the descriptions available athttp://www.redhat.com/software/rhn/ .1. Document ConventionsWhen you read this manual, certain words are represented in different fonts, typefaces, sizes, andweights. This highlighting is systematic; different words are represented in the same style to indicatetheir inclusion in a specific category. The types of words that are represented this way include thefollowing:commandLinux commands (and other operating system commands, when used) are represented this way.This style should indicate to you that you can type the word or phrase on the command lineand press [Enter] to invoke a command. Sometimes a command contains words that would bedisplayed in a different style on their own (such as file names). In these cases, they are consideredto be part of the command, so the entire phrase is displayed as a command. For example:Use the cat testfile command to view the contents of a file, named testfile, in the currentworking directory.file nameFile names, directory names, paths, and RPM package names are represented this way. This styleshould indicate that a particular file or directory exists by that name on your system. Examples: