Linux Desktop Hacks

Build a Custom Firewall Computer #81

Chapter 9, Administration and Automation

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247

HACK

HACK

#81

Build a Custom Firewall Computer Hack #81

Turn an old, underpowered computer into a lean, mean, firewall machine.

As more and more computers are getting plugged into the Internet, the risk

factor associated with an online presence has also risen. The increase in

hours online combined with the propagation of always-on broadband and

high-speed cable/DSL Internet access has resulted in the need to secure even

simple, one-computer home networks. As a result, the humble firewall has

become a must-have item as opposed to a could-have item in a network.

The basic aim of a firewall is to keep unwanted people off of your network.

The virtual wall of fire is essential in keeping out crackers who want to

invade your security, as well as blocking the growing armies of worms,

viruses, and other Internet nasties that crawl the Web looking for comput-

ers to exploit. The situation is very bad; an unprotected Windows machine

can become infected in as little as four minutes after it is put on the Inter-

net. If you are considering a firewall but are uncertain you want to put the

effort into it, ask a friend who has one for a list of attempted intrusions on

his network. You will probably be surprised by the frequency of attacks. My

own firewall logged more than 100 attempted intrusions in the first few

hours after I put it ...