http://en.wikipedia.org/wiki/Virtual_hosting
We do not hard code/keep the machine name for AgilePoint Server (front end web server) in database or registry. You can have multiple URLs that point to the same IP address of AgilePoint Server machine, the workflow engine works fine in this case.
We recommend you to test the vDNS migration scenario on a staging/testing environment first, this is to collect any environment specific issues and the resolutions before working on your production environment.
For more information, see General Guidelines for Migrating AgilePoint Server to New Hardware.