Multisite

Hello. I have an issue with setting up Multisite. When I attempt to access the site without "www" I can a page from the site that displays a signup form with the message "The site you were looking for .... does not exist.

Please advise if this can be solved by a plugin or it remains in the setup of the network. Below is the URL.

Respectfully,
Steve

Working URL: http://www.intermediacloud.com/
Issue (without http://www): intermediacloud.com