Chapter 9: Building Networks

Overview

If you re going to share resources among computers efficiently , the use of networks is essential. Networking is a complex topic, but it s powerful, and these days it s indispensable . For example:

• At work, it s hard for many corporations to imagine life without the large networks that make files and services accessible to their employees .

• At home, if you ve got a couple of computers, the convenience of having them networked together for sharing files is immeasurable. (Plenty of network professionals started out by tinkering with small home networks.)

• Networking is also what makes the Internet possible.

Linux is a popular choice these days when it comes to enterprise networking solutions. Linux networks are fast, reliable, secure, and cost effective. Google ( www.google.com ) provides one of the best examples of enterprise Linux networks. Google s search engine comprises more than 10,000 servers networked together to form one of the world s biggest distributed computing systems, and the world s largest commercial Linux cluster. The Stone SouperComputer is another (rather different) example of what is possible with Linux-based networking (see http://stonesoup.esd.ornl.gov/ ).

This chapter begins with a general discussion of networks, and the advantages of using Linux for building networks. Then, sections are devoted to each of the following services:

• Setting up a Web server, for hosting Web sites (or, if you re planning to develop Web sites, to test your sites as you build them)

• Setting up an FTP server, a place from which users can download files and/or upload files

• Setting up a Print server to manage printers and enable them to be shared among multiple users

• Setting up a File server to share files (for example, between Windows and Linux systems)

• Setting up a Mail server, for delivering e-mail to its final destination (for example, you could use an e-mail client on a Windows 2000 laptop and configure it to send and receive e-mail via a local Linux mail server)

• Setting up a DHCP server, which automatically assigns network settings to connected systems

You may choose not to read all of this chapter, but only the sections that relate to the services you re interested in. You probably won t need all these services on your Linux machine, and you re not obliged to set them all up. (In fact, there are good security reasons for choosing not to set up a service unless and until you need it to be there. Security is further discussed in Chapter 10.)

Moreover, these services all work independently of one another, so (for example) you don t have to set up an FTP server for your Web server to work. You can enable and disable any service just at the time you need it.

By default, Fedora 2 setup provides you the option to configure the firewall. If the firewall has been configured, you might face some problems accessing the services set up in this chapter. After setting up or configuring any of the services discussed in this chapter, you should always check the firewall settings and, if needed, open the ports to enable access to those services. Please refer to Chapter 10 of this book for more information about setting and configuring the firewall.