DNS stuff!
 

http://www.dnsstuff.com/

Handy tools. :)

It's good for making sure all of your hamsters are configured properly

Great tool, used it for years.

good stuff :thumbsup

good site

Definitely comes in handy. We point a lot of our customers towards that site as it helps them greatly in figuring out of their DNS is working properly, what exactly the problem is, etc. it generally helps them get a much better understanding of the process.