How can I fix Open DNS Resover issue

Did a check at http://www.thinkbroadband.com/tools/dnscheck.html and got following.

Warning! We detected your IP address as xxx.xxx.xxx.xxx and found an open DNS resolver running.

This may be either running on your computer or on your broadband router. It is advisable that you don’t run a resolver which can be queried from the Internet. It is possible that you could be vulnerable to a DNS poisoning attack. More details are available in the CERT Advisory or you can carry out a more detailed test at doxpara.com or dns-oarc.net.

There was Opened port 53 is problem? but I can’t guess if the cause is similar in your case…

Thanks that helped resolve the issue.