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Using
ZoneAlarm
by: Olen Soifer
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We suggest that
everyone who uses the internet get a firewall. Firewalls control who has access to your
computer or network from outside the network, via the internet, etc.
ZoneAlarm
is just one that is available and is free for private use. We like this program
and, while the free version is quite good, you may want to consider the pay
version: If you think you may have
been "hacked" (broken into from the internet), you should
perform a search of your PC &/or network to see if the hacker has
installed a hidden web server such as Back Orifice on it. With no
firewall and BO installed, your hacker can access your machine as if he
were sitting right at your keyboard...write, change, delete files;
change settings, etc. Click
here for more information on
dealing with BO type
servers.
Very briefly, a firewall, like Zone Alarm, divides the "worldwide network" into 2 zones. One zone is
your PC or your network and the computers in it. The other zone is the internet and other computers
you connect to via dial-up network access. Zone Alarm acts as a firewall between the two
zones. It allows or prevents access between the two zones depending upon what permissions you grant it.
ZoneAlarm also includes protection from certain email attachments that use
visual basic codes to rename or delete files on your PC.
Zone Alarm runs itself. However, the first few times you go to the internet, a pop-up may appear that says something like "Do you want to allow
[Netscape] to access the internet?". The program could be anything. I just used Netscape as an example. You should say yes to the question
each time it appears. You are authorizing access permission for the programs that you run that need internet access.
You can also click the checkbox so that it does not ask about that
particular program in the future (if you are sure it is OK to always give it
access to the internet).
HOWEVER, if you see something like this.......... The firewall has blocked internet access to your computer from [IP 123.123.123.123]".
That means an outside machine is attempting to access your machine. Each
place where I wrote 123 is called an "octet". As you can see,
there are four of them and each octet can be any number from 0 thru 255
(about 4 billion different possible combinations). Occasionally, that
warning is as harmless as your ISP attempting to send you a page or
something that you requested. But it may be a hacker attempting to access
your PC.
You should know what your IP number is. This is the number
you are assigned when you connect to the internet. You can find out what it
is by right-clicking the small "on-line" indicator on your
"start" bar. It is probably near your small clock. Then click
"Open Dial-up Monitor". Click the Summary tab and then click
Details. You will see your IP number. This is your address while you are
online. Some ISP's assign a permenant number to you when you choose them.
Others use dynamic addressing which changes each time you log on. However,
in dynamic addressing, usually, the first two octets are always the same.
That is the basic address of the ISP itself. A large ISP like America Online
can have a number of addresses, however. Now, if you see that you are
getting a warning that your ISP is attempting to access your computer, you
can relax.
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3-15-2006 |
