Introduction

The Red Hat Linux distribution has become one of the major Linux distributions, bringing to the PC all the power and flexibility of a Unix workstation as well as a complete set of Internet applications and a fully functional desktop interface. This book is designed not only to be a complete reference on Linux, but also provides clear and detailed explanations of Linux features. No prior knowledge of Unix is assumed; Linux is an operating system anyone can use.

Red Hat has split its Linux development into two lines: Red Hat® Enterprise Linux® and the Fedora™ Project. Red Hat Enterprise Linux features commercial enterprise products for servers and workstations, with controlled releases issued every two years or so. The Fedora Project is an Open Source initiative whose Fedora Core release will be issued every six months on average, incorporating the most recent developments in Linux operating system features as well as supported applications. The Fedora release consists entirely of Open Source software. Development is carried out, using contributions from Linux developers, allowing them to promote enhancements, new features, and cutting-edge applications. The project operates like other open source projects, with releases keeping pace with the course of rapid online development. Unlike Red Hat Enterprise Linux, the Fedora Core version of Linux is entirely free, though not supported by Red Hat, Inc. You can download the most current version, including test betas, from fedora.redhat.com. The Fedora Project release will replace the original entry-level Red Hat Linux distribution. The Fedora Project will also provide Fedora extras, software that enhances the core collection, and Fedora alternatives, popular alternatives to core software applications.

The Red Hat Enterprise line of products is designed for corporate, research, and business applications. These products focus on reliability, stability, and performance. They are released on a much more controlled schedule than the Fedora Project versions. What was once the low-cost consumer version of Red Hat Linux will be replaced by a scaled-down commercial Enterprise version for consumers and small businesses. Red Hat offers three Enterprise versions: one for the workstation and two for servers. Red Hat Enterprise AS provides the highest level of support from intense mission critical requirements for all aspects of network support, including servers, databases, and security. Red Hat Enterprise ES provides a similar package but one geared to mid-level business requirements. The Red Hat Enterprise WS implements a workstation with a wide range of clients that can be used for either Red Hat Enterprise ES or AS networks.

This book covers the current Fedora Core release, while maintaining compatibility with Red Hat Enterprise Linux. The complete Fedora Core release is provided on the DVD-ROM included with this book. This book identifies seven major Linux topics: Basic setup, environments, applications, security, servers, system administration, and network administration. Whereas the book details the latest Red Hat tools, desktops, and kernel featured in the Fedora Project, it also covers in depth the network servers, administrative tasks, and applications featured in Red Hat Enterprise Linux. The book can be used as a comprehensive reference for both Red Hat Enterprise Linux and the Fedora Project.

The first two sections of the book are designed to cover tasks you would need to perform to get your system up and running. After an introduction to the working environment, including both GNOME and KDE desktops, you learn how to quickly update your system, manage users and groups, and set up your printer using the Red Hat administrative tools. The software management is nearly automatic, letting you install software on your system, including applications, with just a couple of mouse clicks. Internet access can be set up for modems, DSL, wireless, and Ethernet networks with easy-to-use administrative tools that guide you every step of the way. Many people now use Linux to set up a home or local business network. The steps involved to implement a basic network can now be carried out using simple software tools. You can even install Bluetooth devices. All these topics are covered in greater detail later in the book.

GNOME and the K Desktop Environment (KDE) have become standard desktop Graphical User Interfaces (GUI) for Linux and are noted for their power, flexibility, and ease-of-use. These are complete desktop environments that are more flexible than either Windows or the Mac/OS. You can install both, run applications from on the other, and easily switch from one to the other. Both have become integrated components of Linux, with applications and tools for every kind of task and operation. Instead of treating GNOME and KDE as separate entities, GNOME and KDE tools and applications are presented throughout the book.

Linux is also a fully functional Unix operating system. It has all the standard features of a powerful Unix system, including a complete set of Unix shells such as BASH, TCSH, and the Z-shell. Those familiar with the Unix interface can use any of these shells, with the same Unix commands, filters, and configuration features.

For the Internet, Linux has become a platform for very powerful network applications. With Linux you can become a part of the Internet by creating your own Web and FTP sites. Other users can access your Linux systems, several at the same time, using different services. You can also use very powerful GNOME, KDE, and Unix clients for mail and news. Linux systems are not limited to the Internet. You can use it on any local intranet, setting up an FTP or Web site for your network. Red Hat Linux comes equipped with variety of fully functional servers already installed and ready to use.

A wide array of applications operates on Red Hat Linux. Numerous GNOME and KDE applications are continually released through their respective Web sites. The GNU general public licensed software provides professional-level applications such as programming development tools, editors, and word processors, as well as numerous specialized applications such as those for graphics and sound. A massive amount of software is available at online Linux sites like sourceforge.net where you can download Open Source applications and then easily install them onto your system.

Since this book is really five books in one—a user interface book, a security book, a server book, a networking book, and an administration book—how you choose to use it depends upon how you want to use your Red Hat Linux system. Almost all Linux operations can be carried out using either the GNOME or KDE interfaces. You can focus on the GNOME and KDE chapters and their corresponding tools and applications. On the other hand, if you want to delve deeper into the Unix aspects of Linux, you can check out the Shell chapters and the corresponding shell-based applications in other chapters. If you only want to use Linux for its Internet services, then you should concentrate on the Internet clients and servers. If you want to use Linux as a multiuser system servicing many users or integrate it into a local network, you can use the detailed system, file, and network administration information provided in the administration chapters. None of these tasks are in any way exclusive. If you are working in a business environment, you will probably make use of all three aspects. Single users may concentrate more on the desktops and the Internet features, whereas administrators may make more use of the security and networking features.

Part I of this book is designed to help you start using Red Hat Linux quickly. It provides an introduction to Red Hat Linux along with a listing of Linux resources, including software repositories, documentation sites, newsgroups, and Linux news and development sites. The next chapter covers the streamlined installation procedure for most distributions, which takes about 30 minutes or less. The installation program from Red Hat provides excellent commentary, describing each step in detail. In this section you also learn the essentials of using both GNOME and KDE, along with the basics of working on the shell command line. System configuration tasks like adding printers and creating new user accounts are presented with the easiest methods, without much of the complex detail described in the administration chapters that is unnecessary for basic operations. Basic network configuration tasks are discussed such as setting up a LAN, DSL, or Wireless connection to an Internet Service Provider (ISP). You also learn the basics of how to set up a small local network.

Part II of this book deals with Red Hat Linux environments. Here you are introduced to the different kinds of user environments available for Linux, starting with KDE and GNOME. Different features such as applets, the Panel, and configuration tools are described in detail. With either of these interfaces, you can run all your applications using icons, menus, and windows. At any time, you can open up a terminal window through which you can enter standard Linux commands on a command line. You can also choose to use just the standard Unix command line interface to run any of the standard Unix commands. Next, the BASH shell and its various file, directory, and filter commands are examined.

Part III of this book discusses in detail the many office, multimedia, and Internet applications you can use on your Linux system, beginning with Office suites like OpenOffice and KOffice. The different database management systems available are also discussed along with the Web site locations where you can download them. A variety of different text editors are also available, including several GNOME and KDE editors, as well as the Vim (enhanced VI), gvim (graphical Vi), and GNU Emacs editors. Linux automatically installs mail, news, FTP, and Web browser applications, as well as FTP and Web servers. Both KDE and GNOME come with a full set of mail, news, FTP clients, and Web browsers. There are also many independent mail clients, newsreaders, and Internet tools you can easily install from your desktop.

Part IV demonstrates how to implement security precautions using encryption, authentication, and firewalls. Coverage of the General Public License Privacy Guard (GPG) shows you how to implement public and private key based encryption. IPsec tools let you use the IPSEC protocol to encrypt and authenticate network transmissions. Network security topics cover firewalls and encryption using netfilter (iptables) to protect your system, the Secure Shell (SSH) to provide secure remote transmissions, and Kerberos to provide secure authentication.

Part V discusses Internet servers you can run on Red Hat Linux, including FTP, Web, and DNS servers. Internet servers have become integrated components of most Linux systems. Both the standard vsftpd FTP server and the ProFTPD server with its directive format are presented, covering features like guest and virtual FTP sites. The Apache Web server chapter covers standard configuration directives like those for automatic indexing as well as the newer virtual host directives. Sendmail, Postfix, IMAP, and POP mail servers are covered. The INN news server, CUPS print server, the Squid proxy server, and the ht:/DIG search server are also examined.

Part VI discusses system administration topics including user, software, file system, device, and kernel administration. There are detailed descriptions of the configuration files used in administration tasks and how to make entries in them. First, basic system administration tasks are covered such as selecting runlevels, monitoring your system, and scheduling shutdowns. Then aspects of setting up and controlling users and groups are discussed. Presentations include both the GUI tools you can use for these tasks and the underlying configuration files and commands. Software installation has been simplified with package management systems like the Red Hat Package Manager (RPM) and redhat- config-packages. Then, different file system tasks are covered such as mounting file systems, selecting device names, configuring RAID devices and LVM volumes, and using CD and DVD R/RW drives. Device configuration covers topics such as device files, installing printers, and using the kernel modules to support new devices. Using, updating, and configuring the Linux kernel with its modules is covered in detail along with procedures for installing new kernels.

Part VII covers network administration topics such as configuring remote file system access and setting up firewalls. Configuration files and features for the Domain Name System (DNS) and its BIND server are examined in detail along with features like virtual domains and IP aliases. With Linux you can easily set up your own Domain Name server for a local network. You also learn how to implement your own Dynamic Host Configuration Protocol (DHCP) server to dynamically assign hosts IP addresses. The various network file system interfaces and services like NFS for Unix and NIS networks are presented. The chapter on Samba shows you how to access Windows file systems and printers. Then, the different aspects of network administration are discussed such as network connections and routes, Domain Name services, Hostname designations, IP virtual hosts, and IP masquerading. Finally, there is an appendix covering what is available on the DVD-ROM included with this book.