Peoii’s Place

Ahh yes, Firewalls, end users all to often get these visions of this great flaming pire which is impossible to break thru unless you know the secret code word, and are surrounded by a +10 ice shield. To many people think these little marvels are the be-all-end-all of securing your system, so much so that they actually believe that the more they hide behind, the safer they are from all forms of intrusion. How much farther from the truth could they be? I dunno, it’s a pretty long way across the galaxy.

Simply put, a firewall blocks ports. What is a port you say? Well, it’s something that every computer has bunches of, and no, they’re not the places that the cables are coming out of the back of your computer. They’re “virtual” ports, and they’re so important to the modern age of computers that most programming langauges treat them as nothing more than a file when they’re opened. That’s right, a file, the most basic of items on a computer, and a port is just that simple, except in that a port reads from a remote location, where as a file is typically stored locally on your hard drive. So by accessing this website, your computer used a port to read the information the server hosting this website was sending at it, and yet this happens millions of times per day per person, and it’s not a bad thing, so why do we bother having firewalls? The answer is simple really, you only want the ports open that you want to be able to use, and the rest? Well, left unattended, they allow hackers and malicious software into your computer without your knowledge or consent.

So what exactly does a firewall do? It gives you a method by which to close or “stealth” these ports from incoming traffic. Heck, some of the newer ones even allow you to block outgoing traffic, so you can know exactly which programs are accessing the internet, and why. Does this affect your surfing ability? Not for most people, as when you’re checking your email, or surfing the web, you’re not typically touching something that would be blocked by a firewall. But for instance, if you’re sharing files over a network with people, then yeah, it might affect things, but once you have it properly configured, you’ll be able to state what ports you want to allow, and in some cases, who you want to allow to access specific ports. That gives you control over your computer, and as much as control freaks are typically a bad thing in the world, in computers, they’re very smart people.

Before we get to far, we should go into the difference between closing a port, and stealthing it. See, a port really only has two states, it’s either open or closed, and if it’s open it can accept data, if it’s closed it can’t and the request is denied. But that in of itself is kind of a flaw that it actually reports back that it is closed, because then the hacker knows your there, and can attempt to find another port to attack you with, or use a different method. Where stealthing comes into play is instead of reporting back that the port is closed or open, it just eats the request, and doesn’t report anything back, so it’s like your system isn’t even there. That’s a very useful thing, and many more firewalls are starting to allow this type of protection, as it’s far safer to simply not be there, than to report back as a closed up shop.

_{Linksys BEFSR41 Router}

So lets start with the basic idea of what type of firewalls are out there, which really boils down to two categories. Software Firewalls, and Hardware Firewalls. If you’ve ever wanted that flaming pire to stand between you and the hackers at large out there, then you’ll definately be in the market for a Hardware Firewall, as these suckers are increasingly difficult to get thru, and rightfully so, since it’s not taxing your computer to fight the attacker, and the attacker has no way of getting to your computer without going thru that device, you’re pretty well secured behind it. So how do these work? Well there are many different methods that they use, and the most common of them is what is known as Network Address Translation, or NAT as it’s refered to in many manuals. Basically this takes the 1 IP address your internet provider has given you, and it breaks it up for each computer that is connected to the NAT enabled device, thereby allowing you to have mutliple computers online at the same time. How does this work as an effective firewall? Well, since the attacker is typically trying to go after an actual computer and not some little box on your desk, it has no idea that it’s actually attacking that, and not your computer, and since NAT enabled devices hide your internal IP from the world, there is no easy way to get around that little bit. And for those of you that are worried, no, it’s pretty tuff to break most modern NAT enabled devices, so you don’t have to worry about the hacker destroying your little piece of hardware. So are they foolproof? Not even, the only foolproof method to having your system secure from attack is to never have it online, and that’s just not an option for most people in this digital age. But as far as security goes, these are about the best that money can buy for most users, and sure, sometimes they can get pretty expensive. Though of late, you can find these located in some rather affordable router packages, some of which are located in the table at the end of this course.

So that leaves us with Software Firewalls, and in this category, there are bunches of options that suit every level of user from the novice, to the mega-control freak who wants to be able to script the way his firewall acts. How do these work? Well, they “hook” or “filter” the port, that is to say they intercept the data being trasported along that port, and make sure that it’s allowed to pass thru on that port before sending it and if it’s not, the data falls into the great black hole. Drawbacks? Glad you asked, yes, there are some, afterall this is simply software right? Yup, and that means they require your CPU’s power to drive them, which means that if you’re running on a slower computer than the person attacking you, they have a much better chance of getting past your firewall and into your system. So if you’re on a nice newer system, sure, a software solution might do you just fine, but if your computer is more than about a year or two old, you might consider a hardware firewall as a better course of action. Also, as with any software, you have to keep this software up to date, though that’s not as big of a concern, as you should be keeping all of your software up to date anyway, but it’s one more thing to remember to do.

Amazingly, most people are actually running atleast some form of firewall software, and just don’t know about it. Windows XP actually comes with a respectable personal firewall built into the system, and yet it’s disabled by default, something I’ve always felt is a major flaw in Windows. If you’d like to turn it on, simply go to your Network Connections option in your Control Panel, right click on the connection you want to firewall, and select Properties, then click on the advanced tab, and check the checkbox next to Internet Connection Firewall. And there you have it, a basic firewall is setup on your computer. But suppose you want more power than that? Well, there are a bevy of software solutions out there to help you secure down your system with a firewall, and it all depends on how much control you really want as to which solution is right for you.

_ZoneAlarm

So which firewall is right for you, and what do you need? Well, that varies on the person, but typically if you’re still reading this, you’re only going to need a fairly basic firewall to block you against most attacks. Either the Windows Firewall or one of the solutions listed below should do you just fine. If you’re on a network, I highly recommend the router/bridge solution discussed in this article, as they’re very inexpensive, and very effective for most peoples use. And if you’re looking for something a bit more powerful, check out the items in the firewall software list that I’ve marked with a *, those will indicate more powerful, but more difficult to install software packages.