Firewalls

Everyone who connects to the internet should have one or more firewalls. "What's a firewall?" I hear you ask. A firewall is an item of hardware or software which isolates your computer from the internet by inspecting each packet of data to determine whether it should be allowed to pass or be blocked. You might like to think of it as a wall between you and the outside world, having a small door to allow goods and people in and out, but where someone inspects everything trying to pass to ensure it's allowed to do so. A firewall is the same sort of thing but in network terms.

Types of Firewall

There are two main types of firewall which are relevant; software firewalls and hardware firewalls. A software firewall is a program which you run on your computer. A hardware firewall will normally be combined with a router or gateway. It is an external device which you connect to your internet connection (normally broadband) and to which you connect one or more personal computers on your home network. Both hardware and software firewalls are effective in providing good isolation from unwanted attention on the internet, provided, that is, you choose the right ones.

Software Firewalls

A software firewall is actually a must have item, even if you have a hardware firewall. Why do we say that? Because only something running on your computer can detect attempts to connect to the internet and enable you to block or allow that attempt.

Windows XP built-in firewall

Windows XP has a built in firewall which has been further enhanced in Service Pack 2 (SP2). This is, of course, to be commended. If you have no other firewalls in place you should ensure the XP firewall is turned on immediately. If you have SP2 then you should go to the Security Center (on the Control Panel) and examine the "Firewall" setting. If it's not "On" then turn it on... If you don't have SP2 then I recommend you get it (it's free), see Keep It Clean for information on Microsoft Update. While we like the Windows firewall, it has one glaring omission - it doesn't check traffic leaving your computer, only traffic coming in. While this may not seem such an omission at first sight, (after all we are working on the basis that we want to keep things out) it is in fact quite important because if something does get in then we want to know about it and prevent it causing any additional harm.

Third Party Products

There are quite a number of third party software firewalls available at very reasonable prices. So how do you choose one? Fortunately there are people out there in internet-land who have the time and skill to examine the main offerings and make recommendations. One excellent source of information is Steve Gibson's site www.grc.com. Steve explains the tests he's performed over time and makes a number of recommendations. From his list we recommend the ZoneAlarm products from Zone Labs; the only ones to rate a "Never Leaked" status from Steve. Interestingly, in a recent review on ZDNet Stephen Biglow concluded "ZoneAlarm Pro 5.5 offers the best software firewall and basic security product available to PC users today". You can click on that sentence to read a review while it's still available online.

When you check out the the Zone Labs web site you'll see there are currently 4 products with ZoneAlarm in the name. ZoneAlarm itself is a free version which works rather well. Moving up from there we have ZoneAlarm Pro, which has all the features of the free version and adds a number of others which you may care to have at a cost of US$49.95. Zone Labs have acquired an anti-virus product and so now you can buy the standard ZoneAlarm firewall with one years Anti-Virus subscription for US$24.95 (quite a good deal). Finally there's the all singing all dancing ZoneAlarm Security Suite, which includes the anti-virus and Pro version of the firewall, along with a rather useful tool to assist with instant messenger security called IMSecure Pro. All this for a mere US$69.95. (Remember anything which includes an Anti-Virus product means an annual fee as this is something which needs to be frequently updated).

Ultimately we recommend the ZoneAlarm Security Suite because it incorporates all the features of ZoneAlarm and ZoneAlarm Pro with a good anti-virus tool. This means you get almost all the features we talk about on this site, including the optional areas of blocking offensive sites all in one package. That's not bad and it means keeping things updated is simpler. (And simpler equals less time/effort on your part).

If you want to save some money, we've signed an agreement with ZoneLabs which enables us to offer these products at a discount. While the offer is still on, if you use these links you will get a US$10 discount off the list prices:

• ZoneAlarm Security Suite
• ZoneAlarm Pro

If you'd like to know a little more, see our short review.  If you're still unsure then just download the free version and get that running to get the feel of things. You can upgrade after that if you wish.

Hardware Firewalls

A hardware firewall is just what it sounds like, a piece of hardware whose whole reason to exist is to form a firewall between your home computer or network and the internet. There are a number of items on the market for use, many of which are really only suitable for business customers. For the home user the right sort of device is a firewall which is also a home gateway and router. These devices also perform an important function from the security point of view; they do Network Address Translation (NAT). What that means in practice is that the IP address which is allocated by your ISP is actually the address of the firewall/router and your computer is allocated a hidden address by the firewall/router itself. This is an excellent first line security measure as it means any attacks aimed at you are in fact directed at the firewall/router and that device exists to handle them.

There are a number of good firewall/router devices on the market at reasonable prices. I suggest Netgear, Linksys, Zoom and 3Com make excellent choices. (Paul runs a Netgear FR114P). When we get a suitable opportunity we'll include some links to a few good models, but the Google sponsored links on the right should provide some good input.

Testing to see if your firewall works

Now we've obtained and installed a firewall, the next thing to do is see if it's working! After all there's no point in installing these things and then not know if they really work. So just how do we test a firewall? Well Steve Gibson comes to the rescue again. He has written a test program called "Shields UP!" which, upon your agreement, will remotely probe your computer to see how well it defends itself. To use this tool go to www.grc.com, click the "Shields UP!" logo, then scroll about halfway down to the next page to an area headed "Hot Spots" and select the "Shields UP!" link. Read the instructions and caution nodes and click "Proceed". You'll then be on the main test page. Actually it would probably be instructive to run these tests before enabling any firewall to see just how open to attack your machine is, but please don't leave it unprotected for long.