Recently I have had to configure a virtual environment for IFD to test a MSCRM 2011 solution I have developed. The solution had to work on the internal domain as well as externally. Below I have listed the steps I went through to get IFD working internally and externally on the same machine. Please note that these steps worked for me and my scenario/setup. They may help as a guide for your deployment. This guide expects you to have some knowledge around DNS, Certificate Management, Internet Information Services and Microsoft Dynamics CRM.