Does anyone here explain to me the idea of a firewall....... I want to make a firewall my self.. Does it have something to do with math?
In the meantime, what is the best firewall available today?
I do have a Norton Antivirus.. but it hangs up my system sometimes..
Topic moved to the Software Forum.
The concept of a firewall is actually pretty simple. A firewall looks which programs/applications/services want to acces the internet/network and then decide if that program is allowed to do that or not.
If you want to create your own firewall I suggest you google some for "global winsock hook" if you use Windows. You should also know how to identify applications ("process snapshots"). You need to know pretty much about TCP/IP and UDP, because these are the most use protocols of communicating.
It's probably a daft idea to try and make your own firewall; the chance of missing something important is just too great if you're working on your own. I'd highly recommend using a prebuilt firewall; ZoneAlarm for Windows, for example.
| qscomputing wrote: |
| It's probably a daft idea to try and make your own firewall; the chance of missing something important is just too great if you're working on your own. I'd highly recommend using a prebuilt firewall; ZoneAlarm for Windows, for example. |
If I was to build a firewall, I'd do it for my own sake and to challenge myself, hopefully learning a lot, not to make a product to sell or something like that. I suspect this might be true for the OP as well - go to any technical library, they will have tons of books about network security and things like that.
Hi!
Consider that writing security-critical applications, such as a firewall, isn't an easy job, especially if you are going to use it on daily-use machines.
Nonetheless it would be a great experience as it would teach you how the network really works. So, if you are really interested in developing a firewall, please buy or download all the specifications of the most used procotols (TCP/IP and UDP), read them and UNDERSTAND them. Then you will be sure to write a powerful
and efficient firewall.
Good luck! 
I hear that the Firewall that you can get from Microsoft that you have to pay for works very well, but Norton, and all of the other popular ones are highly suggested that you DO NOT buy. They are a waste of money. THey might be the best out there, but since they are the most popluar, they are the ones that get hit the hardest.
For a good firewall, I suggest you get a good one that isn't very popular. I am using one that Norton bought out years ago, yet my dad's PC still gets a huge load of Virus's, while mine doesn't. SO the firewall I would say I suggest, Sygate Free Edition. (Can be found at www.majorgeeks.com ) Also, if you are wanting good security, also get AVG ( www.free.grisoft.com )
Both of those are free, and use hardly any RAM, and work great. AVG can be upgraded if you pay for it, but you cannot upgrade Sygate due to Norton buying it out. Sygate has been forgotten, so it isn't really attacked at all.
Please try to keep on-topic (ie. how to create a firewall from scratch). If you want to discuss the best / worst security software, including firewalls, please use the official Security Software thread - it's a sticky at the top of this forum.
Jetico (tough to configure), Commodo and Zone Alarm Pro are good ones.
Test your firewall yourself. Just to go www.firewallleaktester.com and run the 19 tests. Dont worry, they are safe.
On tip of advice when creating a firewall, when I tired to create one I tested it on my coding computer, little did I know it would make OS damage so try to get a computer for testing needs. It better to be save then sorry!
You may want to consider an external firewall for a windows computer. I recommend a pfsense or m0n0wall-powered, low-power embedded device.
This one caught my eye recently:
http://linux.jjplus.com/index.html
Only uses 2 watts!!!!

| Indyan wrote: |
Jetico (tough to configure), Commodo and Zone Alarm Pro are good ones.
Test your firewall yourself. Just to go www.firewallleaktester.com and run the 19 tests. Dont worry, they are safe. |
I use Zone Alarm Pro (Registered), but it does have some conflicts with other software....but all-in-all it's a pretty good firewall, as of this writting it has blocked 12,547 attempts at access to my system....not too shabby. 