Updated: December
28, 2002
Back in the days
of dialup connections to the Internet (no offense to those
still on dialup), you didn't really have to worry about
hackers because every time you dialed into your provider,
they would give you a new IP number. Today with DSL and
Cable, you may have a static IP number that never changes
or if you have a dynamic one, that number may not change
for months at a time. This gives hackers a chance to come
back to your IP number if something looks interesting to
them.
How are hackers
going to find your IP number? Well, if you have a domain
name, finding the IP number is as simple as doing a nslookup.
Even if you don't tell anybody about your IP number, you're
still in trouble. Hackers don't sit there and manually
try every IP number in the world, they have written software
programs that will do that for them. Once they find an
interesting IP number, they can then scan through all
your port numbers to see which ones are available for
attack. This is also done by software.
If you want
to see how exposed your computer is, go to grc.com and
click on "Shields Up". Test your shields (and photon canons)
and then ask them to "Probe your ports". You may be surprised
at what information they can show you.
The chances
are slim that you'll get hacked right? Wrong. Let me tell
you a little story. I put together a server to server
streaming audio. I installed windows 2000 advanced server
and applied the sp1 service pack. I the connected the
server to the network and within 10 hours, somebody had
started to use my server as a storage space for his pirated
material. Apparently the default settings in windows 2000
allows many openings to the outside world and he found
a way in. (Linux users must love this story). 10 hours!
Can you believe that?
A firewall
is a must.
Some people
use software firewall programs and other people use hardware
routers with firewall protection. My recommendation today
is to use both. A hardware router will put distance between
your computer and the Internet and also afford protection
by method of NAT. Then each computer on your network should
be running a software firewall. This will offer maximal
protection from the elements.
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