Anders,
I would first suggest that you join the new server to the domain as a Member
Server and then run DCPROMO on it so that it becomes a DC ( let's call it
'DC2' ). Make sure that you have given it a static IP Address ( not sure
what you mean by 'external' IP Address ) and that you include ONLY your
Internal DNS Server(s) IP Address(es) in the TCP/IP Configuration settings.
The only place for any external DNS Server ( such as your ISP ) information
is in the Forwarders tab.
Install DNS on it as well as WINS ( do you need WINS? Do you have
down-level clients - WIN9x/WINNT 4.0 - in your environment? ) as well as any
other 'services' ( possibly DHCP? ). Consider using Active Directory
Integrated DNS ( aka Dynamic DNS aka DDNS ). This might be a good choice
here.
I might suggest that you also create a Reverse Lookup Zone in DNS ( also
Active Directory Integrated ).
I would then make sure that DC2 is also a Global Catalog Server.
How To:
http://support.microsoft.com/?id=313994
If you have not already done so I might set up Active Directory Sites and
Services.
How To:
http://support.microsoft.com/?id=318480
Once you have all of this done and have made sure that everything has
replicated to the new DC I would manually transfer all five of the FSMO
Roles from DC1 to DC2. You can do this with the various MMCs or via
NTDSUtil. NOTE: you do not really need to do this as the dcpromo process
*should* transfer any of the FSMO Roles that the DC that you are dcpromoing
to the other DC in your environment. However, I like to manually do this so
that I can control this part of the process better.
Using NTDSUtil
http://support.microsoft.com/?id=255504
Using the MMCs
http://support.microsoft.com/?id=255690
I would then make sure that any user folders/files et al were somehow moved
over from DC1 to DC2 ( xcopy is a possible tool for this ) - if you plan on
removing this server from the Domain entirely.
Once I was sure that all of this happened I would simply dcpromo DC1 down to
Member Server status. Are you going to completely remove this server from
your environment or are you simply removing it from "DC-status"?
HTH,
Cary