The newly disclosed fact that site load times (responses) affect seo results has had me looking for a good dns check tool. Without doubt, and after hours of searching and testing this dns check has proven to be the best i found. This is not my site, and i have no affiliation with it, it is simply a good service and another tool in the box. Yes i know it is only a small issue but why not avoid it.
DNS is one of the most overlooked problems with a site. Here is another link to a similar tool: http://www.dnssy.com/ Chris