by Darryl Brooks

Created on: June 06, 2010

When troubleshooting internet connection issues, you may be asked to supply your DNS server addresses. The first questions you may have are what a DNS address is and why you should care. DNS stands for Domain Name Service and refers to a series of computers on the internet that tells the Internet where a particular domain is located. As you may know, the Internet uses unique IP addresses to identify every computer attached to it. Since no one can be expected to remember the over four million IP addresses available under that numbering scheme, that’s where Domain Name Servers come in.  It’s their job to know that, for instance, Google.com is located at 74.125.67.104.

As to why you should care, one of the way viruses can hijack your browser is by sending you to their site instead of the one you wanted. This can be relatively harmless when the hijacker takes you to a porn site instead of your favorite search engine. But it can be much less harmless if it takes you to a site that looks like your banking or credit card company, but is in fact a fake site intended to steal your identity. One of the ways this can be accomplished is by changing your default DNS server to one of their own.

Here is a brief and simple explanation of how a DNS server works. Let’s say you type google.com into your browser address window. Your browser will check your computer’s network connection and determine whether you have a static DNS server or it needs to get that information from your Internet Service Provider (ISP).  Either way, It then goes to that server and asks, “Where can I find google.com?” The DNS server replies with the IP address. The browser can then find the internet address you have typed into your browser. Now let’s say your computer becomes infected with a virus. For most web sites, it doesn’t care and sends you on to the site you requested. But based on certain keywords it knows when you are trying to get to a bank or credit card site and instead of sending you to mybank.com, it sends you to phoneybank.com. The problem is the site looks so real, you don’t know the difference. Now it has your log-in information to your bank account.

So back to the original question, where do you find your DNS servers? Depending on your version of Windows, there are several ways of finding this information. The bad news is there are quite a few steps to get there, and if you click on the wrong thing, you can create other problems. The good news is there is a simple and fool-proof way to get this information. Click on Start, Run, in Windows XP, or just the start icon in Vista or Windows 7. Type in CMD in the text box and hit enter. This will bring up a black text window. Type in ipconfig /all and press enter again. This will create a listing of words and numbers that will probably look like gibberish. Scroll up just a bit and you will see a line that says DNS servers. To the right of that are two IP addresses. This is the information you are being asked about. Keep this window open as the person asking about your DNS servers can also find other useful data here. Protecting your DNS server information is just one day to foil viruses and hackers.

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