Free Public DNS Servers

Free Public DNS servers are a great gift to the internet community and home users should make use of them whenever they can. For those of you who don’t know what DNS servers do, they help you surf the web more easily. If you want to get to Walmart.com, you type in “walmart.com” to your web browser and voila- you’re at walmart.com a second later. Behind the scenes what just happened (measured in milliseconds) is your computer sent a message to a Domain Name System server and said “what IP address is walmart.com?”, the DNS server replied “161.170.244.20” so then your PC opens a connection with the IP address 161.170.244.20 to get walmart’s main web page along with all the pictures and text to tell you about their prices and product offerings.

So why does it matter which DNS server you use? Because most free public DNS servers out there don’t think about where they’re sending you to before they give the answer with the IP address. Say you’ve been surfing the web and accidentally caught a virus which installs some malware that wants to turn your computer in to a remote controlled zombie! (see: Illegal BotNet) The malware will try to reach out on the internet to some weird URL like commander.afeawlkjfe.org to receive further instructions about downloading *more* malware programs to further secure the commander’s control over your computer (imagine a burglar breaking in to your house, drinking your beer, eating  your sandwiches then leaving a side and a back window open in hopes that you won’t notice so he can come back later).  Or it may reach out for a small spam generator so it can force your computer to send nasty spam emails to email lists. Or generate bogus traffic to jam up walmart’s website (see: DDoS)!!

How do free public DNS servers help? When you set up your computer’s network connection settings, you can specify  which DNS servers your computer makes requests to. I won’t get in to a lot of detail, but if you choose a DNS server that is aware of those bad URLs (like the commander.afeawlkjfe.org) it will give the wrong IP address on purpose to your computer. So the malware that made its home in your PC can’t call the commander for instructions on what to do next. So unless it has a built in set of instructions, it can’t do much more harm to your PC or the other systems on your network.

Sign me up! How to add the free public DNS servers addresses varies from version to version of Windows or Mac systems. Usually these days you have a modem with a wireless router that will give your computer the DNS addresses as soon as your PC gets on your home network. So to do it the right way, you should set the free public DNS servers at your modem or router. If done that way, every computer in your house will get those DNS servers that you specify.  Below I’ve compiled a list of free public DNS servers that will serve different purposes. Some block malware and viruses, while others are even more protective and even block content inappropriate for minors.

Free Public DNS Servers (no thorough blocking)
Google  8.8.8.8 and 8.8.4.4
Level3  4.2.2.1 4.2.2.2 4.2.2.3 4.2.2.4 4.2.2.5 and 4.2.2.6

Free Public DNS Servers (Some Malware and Virus Protection)
OpenDNS 208.67.220.220 208.67.222.222
Norton Internet Security  198.153.192.40 198.153.194.40

Free Public DNS Servers (Malware, Virus and Some Adult Content Filtered)
Norton Internet Security  198.153.192.50 198.153.194.50

Free Public DNS Servers (Malware, Virus and Most Adult or Objectionable Content Filtering)
Norton Internet Security 198.153.192.60 198.153.194.60

Free Public DNS Servers (For the Privacy Conscious- They promise to delete all web requests within 24 hours)
OpenNIC  202.83.95.227 216.87.84.211 64.0.55.201 184.154.13.11