In this lecture, we’ll be promoting our second domain controller to our domain.

Now, a second domain controller is built for redundancy purposes and for larger networks that you would like to do some type of load balancing or you want to have multiple domain controllers that your users and clients can use.

It can also be useful if you have two different sites, so if you configure Active Directory Sites and Services and you have a location in New York and another in Chicago you may want to promote a Domain Controller in Chicago and have all your users use the closest Domain Controller to their location.

At this point, you should have created your second VM with the Windows Server operating system and you should have configured the computer name and IP address.

Let’s dig into the IP configuration since this is very important.

Open your Ethernet Adapter properties.

NOTE: For the lab use the following network settings for your second domain controller if you are using our IT labs:

We are using an IP address ending in .11 since our primary Domain Controller has an IP ending in .10.

The preferred DNS server is the Primary Domain Controller’s IP Address and that is because it has the DNS Server role installed. That means that when we try to resolve serveracademy.com or ad.serveracademy.com it will resolve to the IP Address of the Primary Domain Controller.

If we do not do this we will not be able to resolve the domain name we are trying to join this server to.

To test we can open a Command Prompt and type nslookup ad.serveracademy.com. What this does is return the IP Address of my primary Domain Controller.

This is possible because we have configured the IP Address of the Primary Domain Controller as the preferred DNS server.

If you have issues joining the secondary server to the domain, check the DNS IP Address of the local server.

Now, let’s promote the server as a Domain Controller. In Server Manager click Manage and select Add Roles and Features.

Click Next on the Before you begin Window.

In the Select installation type window select the radio button Role-based or feature-based installation and click Next.

Select the radio button Select a server from the server pool and click on the server SADC02 and click Next.

Now, for the Server Role select Active Directory Domain Services. This is similar as when we installed our primary Domain Controller. The difference will be when we promote the Domain Controller.

Click on the Add Features button to add all the features for our AD DS server role.

Click Next to continue the wizard.

Click Next a couple of times to get to the Install button on the Confirm installation selection window.

Now we just need the installation to complete to promote this server as a Secondary Domain Controller to our existing domain.

Now that the installation is complete we can click on the hyperlink Promote this server to a domain controller. 

Optionally, if you close the window you can click the flag at the upper right and click the same link there.

Now we are presented with three options. We can add this Domain Controller to an existing domain, add the domain to an existing forest, and add a new forest.

When we first created the first domain we chose to add a new forest. Since we already have an existing domain we are going to choose the first option to Add a domain controller to an existing domain.

Then we type the domain we are adding the server to ad.serveracademy.com.