Stump the Geeks

Control what makes it onto your network – for free

CorrespondentMay 13, 2012 

Paul Rosenberg isn’t a big believer in free computer security solutions.

When it comes to anti-virus software, for example, the owner of Chapel Hill-based repair and support shop Love Your Computer prefers his to come with a price tag.

But when Rosenberg was on the hunt for a good Internet content filter, he found an exception: OpenDNS.

The Web-based service, available at, offers users a free way to protect against certain types of network attacks by filtering out malicious content before it ever gets to the computer. The company also says the service can make browsing faster and more reliable.

The Domain Name System, or DNS, allows networks to interpret easy-to-remember Web addresses like into their corresponding Internet Protocol addresses – the numerical location of the server containing the content you’re looking to browse. DNS services, which actually do the translating, are in most cases handled by your Internet service provider. But by handing the job over to OpenDNS, users can get more control over what their networks access from a service that specializes in the task.

“Because they only do DNS, they have one whale of a network,” Rosenberg said. “They’re just better at it.”

After signing up for a free account, OpenDNS provides step-by-step instructions for switching to the service using your router or your computer (from start to finish, it took me about five minutes to set up on my own system). You can then add your network, track statistics and choose security options – all without having to download any extra applications or run anything in the background.

“All the security, all the content filtering happens on the OpenDNS side before it gets to you,” Rosenberg said. “There’s zero impact on the network or computers.”

Custom options

In addition to faster domain name resolution (which cuts down on page load times), OpenDNS allows users to filter the content coming into the network by choosing a filter level. Setting it to high, for example, blocks adult content as well as pages like social networking sites and “general time-wasters.” Custom options also allow filtering based on a number of broad categories like adult themes and academic fraud.

These options are what initially led Rosenberg to OpenDNS after clients asked him repeatedly for a quality content filtering service.

“The answer was always, ‘I’m not entirely sure.’ A lot of the products you see out there are geared not just to content filtering, but to content logging, keystroke logging and monitoring. A lot of my customers – and myself included – don’t want to know everything their kid types on the computer,” Rosenberg said. “I just want to know that he’s not going to be able to view pornography. That’s really what it boils down to.”

Because security is tied into the domain name resolution, OpenDNS can also help guard against phishing sites, which are designed to trick users into providing personal information by mimicking the look and feel of legitimate Web pages. By tapping into its database of known phishing sites, it blocks access to these pages altogether, and can redirect users to a custom page. OpenDNS even provides protection from malware that can exploit vulnerabilities in Web browsers.

Free supplement

Although it can provide good added protection, Rosenberg cautions users not to make OpenDNS their only safeguard.

“It’s not a substitute for anti-virus products, I wouldn’t say that. But it’s certainly an excellent supplement,” he said.

That might be one reason why OpenDNS has seen such wide adoption on big networks. Rosenberg points out that one-third of all schools use it, too, including in his home district of Chapel Hill-Carrboro City Schools.

For Rosenberg, the real value of OpenDNS is that it provides a simple way to put control in the hands of users – and it certainly doesn’t hurt that it’s free.

“This was a lot more about the social aspect of Internet use than it was about technical security,” Rosenberg said. “I know that the kinds of content I don’t want (my kids) to see can’t make it in my house.”

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