Using Linux

Linux can be used to set up any number of server-type systems as well as workstations. This site is primarily concerned with the server aspects of Linux. If you're interested in playing around with Linux as a workstation OS on an older system, pick up a copy of Corel Linux which is based on the Debian distribution and is GUI all the way. The Corel Linux desktop looks a lot like Windows so the transition from using Windows to Linux for a desktop OS will be an easy one. (See the Desktop Linux page for more information on and screen-prints of Corel Linux.)

You can use your Debian Linux software to set up the following types of systems:

• Web servers for external (Internet) or internal (Intranet) use. (We show you how on the Internet Servers page.)
• Mail servers to handle both internal and Internet e-mail. (We show you how on the Internet Servers page.)
• Other Internet-type application servers such as FTP, news, IRC (chat), etc.
• Web cam servers to keep an eye on your home or business operations from a remote location. (We show you how on the Web Cam Server page.)
• Proxy/NAT servers that allow all the systems on a network to share a single broadband Internet connection at home or the office. (We show you how on the Proxy/NAT page.)
• Packet-filtering firewalls which allow you to control what traffic goes out of and comes in to your network (while also performing the proxy/NAT function). (We show you how on the Firewall page.)
• Internal LAN servers for file and print sharing much like Novell or NT/2000. There's even a Linux software package available called Samba that makes a Linux server appear as an NT server to Windows workstations. (We show you how on the LAN Servers page.)
• DNS servers to resolve Internet and/or internal LAN host/domain names. (We show you how on the DNS page.)
• Database servers running MaxDB - formerly SAPDB (free), MySQL (free), or Oracle ($$$$) database software. (We show you how on the Database Server page.)
• Fax servers running HylaFax and utilizing old fax-modems allow all users on your network to send faxes from their desktops rather than printing out a hard-copy to stuff in a fax machine. (We show you how on the Fax Server page.)
• LAN and WAN routers which offer an inexpensive alternative to those $5,000 Cisco boxes.
• Syslog servers which allow you to centralize the monitoring of your network and systems operations. (We show you how on the Syslog Server page.)
• IDS (Intrusion Detection Systems) to monitor your Internet address space for hacking and attack activity. (We show you how on the Securing Servers page.)

Given the free nature of the Linux software and its modest hardware requirements, small and non-profit businesses, schools, libraries, etc. can have all of the computing capabilities and Internet services of big, for-profit corporations with very little financial investment. And Linux is not just for the little guy. Big businesses can save big dollars with Linux because they don't have to pay for all those expensive client access or "seat" licenses (see the server comparison diagram below).

The other benefit to the modest hardware requirements of Linux is that if you do have a fairly powerful machine, you can run numerous applications (such as Web and e-mail and FTP and Telnet and DNS) all on one system reducing your overall hardware requirements. (While it is certainly possible for a single server to handle both internal LAN and external Internet functions, it isn't wise to put both functions on one server for security reasons.)

Support options for Linux-based systems are also growing. Commercial server vendors HP, IBM, and Dell now offer servers pre-loaded with Linux and provide numerous support options for them. Commercial distro vendors have various support packages available and third-party companies offer distribution-specific support options ranging from per-incident to 24/7 contract coverage. For individuals and small businesses, there are free self-help and peer-support options such as on-line documentation, newsgroups, listserves, and chat rooms. We show you how to use one of Debian's chat rooms on the Compiling Software page and Debian support resources are listed on the Resources page.

If you're looking for a career, there are two different categories of jobs working with Linux/UNIX servers, but they can often overlap. You can focus on a career as a network administrator, where you primarily take care of all of the types of systems mentioned above, manage user accounts, access rights to files, etc. The other is as a programmer, where you are writing shell scripts or programs which can be written in a wide variety of languages, with C being the most widely used. These scripts and programs are often used in the middle or "back-end" tiers of "multi-tier" client/server systems to automate things. For instance, Linux/UNIX servers are often used as back-end database servers running Oracle. In large organizations these two aspects are usually segregated with different job titles. In smaller organizations you may end up doing both, which would be the best training you could ask for. Note that a network administrator will find their life much easier if they are a good shell script programmer. The better they are at writing shell scripts the more they can automate administrative tasks on the servers. As more and more businesses learn about the potential for productivity gains and substantial cost savings realized through the reduced licensing costs associated with Linux, those with Linux knowledge will be in greater demand.

That's not to say you have to be into networking or C programming to have any use for Linux. A vanilla installation of most Linux distributions will include the installation and setup of the Apache Web server software. Out of the box a Linux system can act as a test Web server for Web site developers and those who write CGI scripts for Web sites (which you know the value of if you've ever taken down a production Web server hosting 200+ sites with a looping CGI script).

Linux can be useful at home too. It's easy to use it to set up a firewalling proxy server to share a broadband Internet connection with the all of the computers on a home network. (We show you how on the Networking page.) And as long as you've got a Linux proxy box hanging on the Internet, it's just as easy to have your own home Web/e-mail server.

Normally, if you want to set up a e-mail or Web server you have to have a fixed ("static") IP address assigned by your ISP and your own domain name. However, dyndns.org offers a free service called "dynamic DNS" which will allow you to set up your own home Web and e-mail server on a system where the IP address changes (as happens with dial-up, and residential DSL and cable-modem services). You don't even need your own domain name! If you did register your family's name as a domain name you can use dynamic DNS and set up a Sendmail server to receive e-mail for the domain name (ex: homer@simpson.com). Family members would then set their POP3 clients to retreive their mail from this Sendmail server rather than the ISP's. In addition, you can run the Apache Web server software on the system also and host your own family Web site. Information on using dynamic DNS services is given on the DNS page and setting up a Web/e-mail server using the Apache and Sendmail software is given on the Internet Servers page.

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