TYPO3 Core

when I enter mysite.com, it gives me this message "The page isn't redirecting properly

Firefox has detected that the server is redirecting the request for this address in a way that will never complete.

• This problem can sometimes be caused by disabling or refusing to accept
  cookies."

When I go to www.mysite.com, it works fine. My server company says it's something in typo, does anyone know how to fix this, or what information you would need from me to help with this. It's really aggravating.

(issue imported from #M6602)