A customer of mine wanted to minimize the installation of clients and wanted to install the clients using a CNAME and then be able to point this to either the test/education environment or the production environment. We tried it out and it seemed to work (we used the lightweight client of course). However, after a while I found one feature in Outlook that stopped working, the function to invite attendees to a meeting.
If you created a normal appointment in outlook without attendees, and linked it to CRM. All was well, but if you tried to link an appointment with attendees, you got an error message, and the appointment wasn't saved to CRM.
There was a work-around, by first creating the appointment without attendees, saving it, repopening it and adding attendees. You would get the same error message, but since the appointment was created in CRM the first time you saved the appointment, and Outlook sent the invitation the second time. Most of the functionality worked with some extra clicking.
When the client was reinstalled using the same CNAME, this worked, just like it should.
This is a bit strange, I actually hadn't expected it to work at all, but that it worked in general and that just this function did not, was a bit strange.
Please note that even the desktop clients are registered in the CRM SQL Database, which is an indication against trying this techique. Perhaps it would work if it was the same server and the same database, but with a new IP.
Generally I would advise against trying this, and I have heard of people trying to modify the registry to achieve the same functionality (to be able to skip reinstalling clients) but none have succeded as far as I know. If you have, please let me know. I will of course give you credit!
CRM and SharePoint Consultant