Might be a silly question, but it's something I have not done before. We have 3 DC's, 2 2003 and 1 2012 all for the same domain. Can I run up another forest beside it and use the same IP range as the first forest. To be clear I am not planning on creating a DHCP server for the second forest. FYI I am trying to test single signon with an application being deployed currently. The developer is running into issues and blaming on our 2003 DFL, so I want to set up another domain purely at 2012 DFL to see if this is the case. I know I could segregate using VLANS's and vSwitches, but I am just looking to test something really quick and delete it when not needed anymore.
Hopefully what I am trying to achieve is clear enough.