Posted on 01/27/2004 7:46:49 PM PST by maui_hawaii
I would like to learn more about firewalls. I would appreciate any input that knowledgeable freepers can contribute.
First off I am using theWindows XP Firewall.
It says in that link that the firewall blocks all incoming "packets".
First off what is a "packet" and what does it do?
I have checked here but I don't quite get all the lingo yet.
One thing it says in there is:
Before installing personal firewall software on a Windows XP computer, be sure that the firewall built into Windows XP is turned off. Never use two software firewalls at the same time.
Why not run two with each other (namely the XP firewall and say Zone Alarm)?
I have tried Zone Alarm as well as Zone Alarm Pro. It seems all either did was log which programs were accessing the internet. Then again I don't know the first thing about how firewalls work.
If the built in XP firewall blocks incoming "requests" for information (I am assuming this is what a "packet" is) wouldn't that be ok? Whats the danger in leaving it 'as is'?
In the built in XP firewall it has an option to 'log dropped packets'. What does that mean?
Anyway as you can tell, I am curious about how things work and/or how to utilize a tool like a firewall.
Before I fork out the dough, I want to know what I am getting and how to use it.
You know anyone else that would contribute to this thread?
Thanks!
Pretty much all data that is sent over the internet (such as the web page you are reading this reply on) is broken up into separate chunks of a thousand or so bytes. Each chunk, or packet, is sent separately, with a header saying where it is going, and a sequence number. The receiving computer glues the packets back together in order, and sends out requests for copies if a piece is missing.
A firewall watches these low level packets coming and going to your computer, and refuses to let some of them pass (typically, just discards them).
The most basic firewall will let your computer send out any packet, but will only let packets back in that are recognized as replies to something you just sent out.
Zone Alarm goes a bit further, and tracks which applications on your computer are sending what kinds of packets. You can allow your web browser to send requests to web servers (http://... places), but keep some randomly hacked virus infected application from connecting out.
Fancier firewalls will have a lengthy list of rules, saying who can send or receive what from whom when. A place like Amazon, Yahoo or FreeRepublic requires such fancier firewalls. Well, actually many places require such. Pretty much anytime you start providing some service on your computer that others can access from across the internet, you need to get much more serious about firewalls.
This keeps a list of what packets it discarded (filtered out), so you can see what was kept out.
This is just to help you see what is going on.
You connect it between your cable (or DSL) modem and your PC:
They are easier to use, provide a more robust firewall (quite a bit harder to crack) and once installed, can operate pretty much without any consideration for years, regardless of changing and confused settings in your PC.
Zone Alarm tends to go out of its way with the free version to scare you, with various alerts about outgoing packets that are not usually any problem. This encourages you to buy their Pro version.
I did set it up where my network is encrypted and is not able to be seen by others....
Thread over here about Spyware which is another damnable problem that a firewall doesn't help with:
Help Yall,I got a worm i cant get rid of (Cpu Assistance Vanity)
Some more good guides:
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