I am planning on adding a Windows Server 2008 R2 box as a second domain controller for a client running an SBS 2003 R2 domain and have two questions.
Are there any "gotchya's" involved in doing this, or do I just run ad and forest prep, promote the 2008 R2 box?
How would CALs work with this setup? Would I need SBS 2008 CALs, Server 2008 CALs or would the old SBS 2003 CALs cover this setup?
My thinking is I will only need Server 2008 CALs
Question 1:
Instructions for adding a Server 2008 domain controller to Small Business Server 2003 domain
http://technet.microsoft.com/en-us/library/cc708131(WS.10).aspx
The instructions are for SBS 2003 R1 and Server 2008 R1, but the process should be similar. Note that, the 32-bit adprep command on the 2008 R2 media is adprep32.exe.
Question 2:
The previous 2003 SBS CALs will still apply to that server, and are still necessary. For any connections to the 2008R2 box you'll need 2008R2 Standard CALs.
I'm not sure if you can mix CAL types however (User/Device); perhaps someone else can edit that in.