If you are connecting to a sandbox environment of CRM you can’t use an IP in the web address. You need to have a named server that is resolvable via DNS resolution.
Don’t use:
http://216.3.128.12:5557/SmartConnect.svc/
Use:
http://eone.com:5557/SmartConnect.svc/
Here is a link to Microsoft’s article about using a web address with CRM.
https://msdn.microsoft.com/en-us/library/gg334752.aspx
