In this week's episode we take a look at simple DNS based web filtering using a free cloud service called OpenDNS. The services is perfect for those without a big budget to spend on higher priced software solutions like Websese, or web filtering appliances like a Barracuda Web Filter.

Setting up OpenDNS is a snap too. If you are on a corporate network where all clients look to a local DNS server, all you have to do to set it up is set your DNS forwarders to point to OpenDNS's servers which are:

  • 208.67.222.222
  • 208.67.220.220
If you don't have an intenal DNS server, then all you need to do is set your DHCP server (At home it's probably your router) to hand out those IP addresses as the DNS servers for your clients.

Something not mentioned in the video is the fact that this service works with ISP's that use dynamic IP addressing. ISP's like cable companies and DSL for instance often use dynamic IP's. Since your public IP address will change with that, OpenDNS has a utility that you can install on your computer that will detect a public IP change, and alert OpenDNS.

I've used OpenDNS at my last three companies and it works very well for keeping employes in line. It's true that a web filtering service like this can easily be bypassed by statically setting your computer's DNS servers to something else like 8.8.8.8 for instance, but the average user doesn't know that.

What do you use for web filtering in your office? Is it free Is it expensive? Let us know about it in the comments!

Related articles