To be able to configure Windows Server 2012 Domain Controller within Windows 2003/2008/2008R2 network we need to check if Forest Functional Level is set up at least in Windows 2003 mode. This is the lowest required Forest Functional Level allowing Windows Server 2012 Domain Controller installation. That means, Windows 2000 DCs are not supported anymore. Microsoft does not support them with cooperation with 2012 Domain Controllers. It’s time to forget about these old DCs.
We can check this in domain, where we want to install first 2012 DC. To verify that, we need to use “Active Directory Users and Computers” or “Active Directory Domains and Trusts” console.
Using “Active Directory Users and Computers” console, select your domain and click right mouse button (RMB) on it. Choose “Raise Domain Functional Level” and check that.
If you see screen like this (Windows 2003 mode), it means that you do not need to raise your Domain Functional Level. In other case you have to remove all Windows 2000 Domain Controllers or if you have no any, raise DFL to Windows 2003 mode or higher
But remember, raising Domain Functional Level is one time action and cannot be reverted. Before you raise it to 2003 mode, please ensure that all of your Domain Controllers are running at least on Windows Server 2003. In this case all of them are running at least 2003 DCs as DFL is set up to 2003 mode, which would not be possible when any of 2000 DCs are still available.
Windows 2003 mode do not support DCs based on earlier Microsoft Windows systems like NT4 and Windows 2000
Another way for that is using Active Directory Domains and Trusts console. Run this console, select domain for which you want to check Domain Functional Level and choose “Raise Domain Functional Level”
Follow the same steps as in previous console.
More about Raising Domain Functional Level you can find in another article on my blog.
In this place, you can also raise your Forest Functional Level if all of your Domain Controllers in entire forest are running on Windows Server 2003. If not, please skip below steps and go to Single Master Operation Roles section.
To raise Forest Functional Level, select “Active Directory Domains and Trusts” node, click on it RMB and choose “Raise Forest Functional Level”. On the list accept “Windows Server 2003” mode by clicking on “Raise” button.
In this case FFL is set up on Windows Server 2003 mode and there is no need to raise it.
For more information about Raising Forest Functional Level please check another article on my blog.
You can also try to determine DFL and FFL levels following artilce on my blog titled: Determine DFL and FFL using PowerShell
Now, it’s time to determine which Domain Controller(s) hold(s) Single Master Operation Roles. The most important for preparing environment for 2012 DC are
- Schema Master
- Infrastructure Master
We need to be sure that connection to this/these DC(s) are available during set up process. In previous versions we need to prepare environment using adprep command to extend schema and configure Infrastructure Master. From Windows Server 2012 we don’t have to run adprep first. Of course, if you wish, you can still do that but it is not mandatory step. From, now, Windows Server 2012 will do that for you if it will detect that adprep was not used before for Schema and Infrastructure preparation. That’s the newest feature in Windows Server 2012 which simplifies promotion process as much as it can. You need to only check if connection to DC(s) with mentioned operators master roles is available (it is based on similar solution applied in Exchange 2010 where you do not have to use setup.com to extend Schema yourself).
To verify necessary Operation Masters, we can use netdom command installed from Support Tools on Windows Server 2003 (in 2008/2008R2 it is available by default). Open command-line and go to default installation directory:
C:Program FilesSupport Tools and type:
netdom query fsmo
and identify DC(s) from an output
We collected almost all necessary information to start AD preparation for the first Windows Server 2008 R2 Domain Controller. The last and the most important part before we start preparation, is checking Forest/Domain condition by running:
- Dcdiag (from Support Tools)
- Repadmin (also from Support Tools)
Run in command-line on a DC where you have installed Support Tools
dcdiag /e /c /v
and check if there are no errors. If so, please correct them (in case that your forest/domain has a lot of Domain Controllers, please skip /e switch)
now run in command-line:
repadmin /showrepl /all /verbose
to check if your DCs are replicating data without errors.
For more about Active Directory Troubleshooting Tools check one of my articles on this blog
After those checks, you can start with Active Directory preparation.
Adding first Windows 2012 Domain Controller
Before we start preparing AD for new Windows Server 2012 DC, we need to be sure that we are members of:
when we are sure for that, we can start installation.
Install your new box with Windows Server 2012 and configure its IP address correspondingly to your network settings and change default server name to yours.
Remember that it’s very important to properly configure Network Card settings to be able to promote your new box as domain controller!
The most important part of configuring NIC is setting up DNS server(s). Point your new box to one of the existing Domain Controllers where you have installed and configured DNS.
After you verified IP settings, you can start server promotion to Domain Controller. However, you cannot use old good known dcpromo command as it is not valid anymore
Microsoft removed it and now everything is done over new Server Manager console. You need to install Active Directory: Directory Servicesrole and after that in post-installation steps, you can promote it to Domain Controller. Let’s start
Open Server Manager console (if it was not already opened) and click on “Add roles and features” on Dashboard screen
Using default settings in a wizard go up to “Server roles” step (in this article those steps are not described. You may expect their description in another article) and select Active Directory Directory Services role. Accept also default features which are required during installation
Verify if check box is in proper place and go to the next step
On “Features” screen also go to the next step as we do not need more at this step to be installed. All required features will be installed as you accepted them a little bit earlier
Read information about role you are installing and go to confirmation screen to install it
Wait some time until selected role is being installed before you will be able to promote server to Domain Controller
Now, when role is installed, you can see in notification area an exclamation mark. It tells you that post-installation steps might be required
Click on it to see what can be done. You will see that now, you can promote your server to Domain Controller and information that features were installed successfully
OK, let’s start server promotion to Domain Controller! Click on “Promote this server to a domain controller” and you will see a wizard.
As we are adding Domain Controller into existing domain, we need to select proper option. It is selected by default, however, please ensure if you can see that “Add a domain controller to an existing domain” is selected
When you verified that, place in field with red star DNS domain name to which you are promoting DC. Provide Enterprise Administrator credentials and go to the next step
Define if server should be DNS server and Global Catalog. I would strongly recommend installing both roles on each Domain Controller in your environment. Select a Site to which this DC should belongs to and define Directory Services Restoration Mode (DSRM) password for this DC
Do not worry about DNS delegation as this server is not DNS already. Go to the next step
In”Additional options” you can define if you want to install this Domain Controller from Install From Media (IFM) (if you have it) and point from which DC replication should be done. When you do not specify, server will choose the best location for AD database replication. If you have no special requirements for that, just leave “Any domain controller”
Specify location for AD database and SYSVOL (if you need different that suggested) and go to the next step
Now, wizard informs you that Schema and Domain preparation need to be done. As you did not run adprep before, it will be executed in a background for you
You will see a summary screen where you can check all selected options for server promotion. As in Windows Server 2012 everything done over Server Manager is translated into PowerShell code and it is executed in a background, you can check code by clicking on “View script” button. You will see what exactly will be run. This is transparent process and you cannot see PowerShell window in front of you
PowerShell code for adding Domain Controller
# Windows PowerShell script for AD DS Deployment
-Credential (Get-Credential) `
-DatabasePath "C:WindowsNTDS" `
-DomainName "testenv.local" `
-LogPath "C:WindowsNTDS" `
-SiteName "Default-First-Site-Name" `
-SysvolPath "C:WindowsNTDS" `
If all prerequisites will pass and you are sure that all setting you have set up properly, you can start installation
You can observe that Forest and Domain are being prepared by adprep running in backgroun. Wait until wizard will do its job and after server restart you will have new Windows Server 2012 Domain Controller.
Give DC some time to replicate Directory Services data and you can enjoy with new DC.
Now, you need to do small changes within your environment configuration.
On each server/workstation NIC properties configure alternative DNS server IP address pointing to the new Domain Controller.
Open DHCP management console and under server/scope options (it depends on your DHCP configuration) modify option no. 006
Add there IP address of your new Domain Controller as DNS server.
Congratulations! You have promoted your first Windows Server 2012 in existing domain