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Industry Standard Computers
St. Clairsville, Ohio
(740) 695-1520
30 Years In Business - 30 Years Experience with Computers - 25 Years with Networks & Security
The oldest system builder in the area, maybe in the state!
Best Labor Rate in the Area, $25 Shop, $40 Outside

Firewalls... overview:

Firewall is a very generic term in the computer world.  It means a whole lot different things to different people. The following should give a little better basic understanding. This is not "gospel" and is bent a little to put in simple terms for the non-technical people.

Hardware Firewalls:
When you connect to the Internet you have an IP address (telephone number) with 65,535 ports (telephone extensions). Anyone who knows the phone number and extension can call in.

If you have one computer on the Internet. The computer's ports and IP are changed to match the Internet's. Someone calls the Internet IP, they get your PC.

If you have multiple PCs, then all the PCs only get to use one Internet IP. This is called NAT (network address translation) The ports then all basically get closed.  This is the first level of firewall protection. Even some DSL modems or routers do this level if they have multiple CAT 5 plugs (4+) on the back

The second level of firewall translates this internet IP address to a "non routable" (not directly connected) IP address and blocks the majority of ports from external access. If the IP of your computer is 192.168.x.x or 10.x.x.x. you have one of these but still not at a modern firewall level yet; some DSL modems do this too.

Read carefully: You would think "hey, I am safe" at this level. None of the hackers can get in because most of the doors are closed-- wrong.  Most attacks on your computer or system are bought about by YOU going out to the Internet and letting others come back in at the same time. You have been reading these statement for year on Windows Update "would allow remote execution of..." or "would allow a...".

Better hardware firewalls also contain a "set of rules." These "rule sets" are known ways an external source can take control of your internal computer when you contact an external source or Internet server or web site. These are never updated  and give no further protection from the presently invented attacks.  They are in most of the $50-200 firewalls or at least scaled down versions, very common for the $200-1000 range. (We install these in front of our Firewall content Filtering Servers to block out the easy bugs and let our server block the real nasty bugs.)

HOME users are done about here. If you, as a business, is at this level you also need a software firewall on every computer too. On the scale of one to ten (ten best), you are at about 3 and going down each year.

This is also the end of the "preconceived ideas" about firewalls.
Next >>>> Firewalls Hardware Updating Firewalls Software (windows) Firewalls Managed

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Do not copy or use in any way without written permission from Butch Walker.

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