Fix DNS Problems. A Domain Name System (DNS) allows a site IP address (192.168.x.x) to be identified with words (*.com) in order to be remembered more easily, like a phonebook for websites. This service is usually provided by your ISP.DNS. DNS is the backbone of the internet. If your DNS is not setup properly, no one will find you online, send you email or be able to access your online store. Checking DNS is incredibly important, so MxToolbox has created a number of lookups dedicated to checking your DNS configuration. All of these are accessible from our SuperTool interface.