Overview (Diagram 1)
First let’s take a look at the logical network configuration.
There are two NT 4.0 domains with a Two-way trust established between them. There is a PDC, BDC and an Exchange 5.5 server at each domain.
One Exchange 5.5 Organization spans both domains and includes two Exchange 5.5 Sites. We will upgrade Domain -Root by upgrading an NT 4.0 PDC to Windows 2003 and running DCPROMO on it. Though it is going to be easier to upgrade the existing server – PDC/10.10.10.10, we will follow a more elaborate approach.
We will introduce a temporary NT 4.0 BDC – TempPDC (Diagram 2 – the PLAN ), promote it to a PDC, and perform the in-place Windows 2003 upgrade on it. That approach is more convenient because we will not interrupt the users, and they will be able to connect to PDC as usual during the upgrade. It is a safer approach too.
We will keep a BDC shut down, and use it to switch back to the original configuration, in case the upgrade fails.
As the name suggests, TempPDC is going to be used temporary as a DC. It is a very good idea to have a clean installed Server 2003 as a main DC in your forest. Therefore we will add a clean installed Server 2003 – RootDC/10.10.10.15, in the domain, run DCPROMO on it and transfer the FSMO roles to it.
Demoting and removing TempPDC will follow, then moving the resources and services from PDC – like WINS and DHCP.
We will demonstrate how to move and convert the existing WINS and DHCP databases and reconfigure the services so everything will be transparent to the users.
Last, we will delete PDC and BDC, and raise Domain and Forest functional levels.
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