If you are reading this article, you should have a good understanding of how computers work and a working knowledge of how to use Internet tools such as web browsers, Telnet, and e-mail. In addition, you're probably already aware of the . . .
If you are reading this article, you should have a good understanding of how computers work and a working knowledge of how to use Internet tools such as web browsers, Telnet, and e-mail. In addition, you're probably already aware of the need to protect computers on your network from exterior threats, while still allowing your web and e-mail traffic to traverse your connection to the Internet. You may install a firewall to secure your network, but to configure it correctly you must know just how your computer connects to other computers and downloads web pages, exchanges e-mail, or establishes a Telnet session. You'll also need to know how to set firewall rules to differentiate the legitimate network traffic of your network users from the illicit access of hackers and other external threats. As TCP/IP is the mechanism by which your computer communicates with the rest of the Internet, you will need to have more than a passing familiarity with it. This article will give you a better idea of what is going on behind the scenes. But why do you care how TCP/IP works if you aren't a computer programmer or network engineer? You should care, because the hackers attempting to get past your network security often are computer programmers or network engineers (self-taught or otherwise), and in order to stop them you need to understand and correct the weaknesses in TCP/IP or higher-level protocols that they will attempt to exploit. In other words, know what your enemy knows.

The link for this article located at Hacking Linux Exposed is no longer available.