CertiGuide to Network+  9  Chapter 0110: Network Operating Systems (NOS)

Pop Quiz 0110.00 1 Distributions

Perhaps the most misunderstood Operating System is Linux. Loosely, Linux was born from the mind of Linus Torvalds for college students who could not afford to purchase UNIX for school studies. Given this, it should not come as a surprise that the general behavior of Linux is similar to UNIX. Linux is but one of the NOS’s in the UNIX family. There are numerous other variations like Free BSD and Mach, which Apple’s OS X (or OS 10)/10.1 are based on, only with a Mac-style Graphical User Interface.

While the differences among these different UNIX-family operating systems are very real, they can be safely left to the few whom need to worry about very fine distinctions. At the core, they all follow the same conventions. One core piece of information is that they are all primarily (CDI) Command Driven Interfaces. It is possible to put a Graphical User Interface (GUI) of your choice (or in the case of Apple, their choice) to hide the dirty details and use a mouse or other pointing device to configure or operate the OS, but the network administrator will eventually discover numerous tasks than can only be done from the CDI.

For a couple years, Linux was heralded as THE alternative to Microsoft and Windows. A few years ago, when Tcat wrote the first I-Net+ book, Corel was pushing Linux as a replacement Operating System for the desktop. The Linux hype filled every magazine and newspaper. Today, Corel has no Linux as a desktop alternative to Microsoft. This does not mean Linux is dead. It is being found as a replacement in some server environments.

More than one server tossed aside as being too slow to handle the latest and greatest version of Microsoft Windows has found new life as a Linux server, since a Linux server running without a GUI tends to require less CPU power than a Windows server. These “new” old Linux servers are often used as DNS (Domain Naming Service) servers, Web Servers (using the popular Apache free web server software) or even network firewalls. (A firewall can be thought of as a security guard for your network that watches over Internet traffic and protects your network from undesired access – we’ll discuss this more when we talk about security.) Still, more than one front-line engineer has complained to us that Linux is not without faults of its own, which somehow don’t manage to “get ink” as frequently as faults in Microsoft NOS’s.

In late 2001, IBM revealed the extent of its push for Linux as an alternative to Microsoft, Novell and even its own O/S offerings. The IBM has committed over one billion dollars to making Linux a viable alternative.

What that means to us Network+ folks is we will continue to live in a heterogeneous environment, as we have since the beginning of computer networks. Given this, let’s look at what we need to know about Linux and all its cousins.

Pop Quiz 0110.00 1 Distributions