Add a Directory Connection under System -> Settings -> Directory Connections and click Test Connection, as shown below (be sure to use the correct port for your AD):
Navigate to System -> Users -> Data Sources
Click Add -> AD Logins Source, named "AD User Logins" as shown below and click Submit
Navigate to System -> Users -> User Groups
Click Create New Group, name it "DLP Admins", and configure the highlighted fields as shown below and click Save
Navigate to System -> Login Management -> Roles
Click Add Role, name it DLP Admins and select Server Administration under the User Privileges section
Move to the Users & Groups tab and select User Groups -> DLP Admins and click Save
Navigate to System -> Users -> Data Sources
Select the checkbox next to the AD User Logins data source and click the Import button in the toolbar
The imported users will now be added to the DLP Users (in the ProtectUser table in the database). You can view them from the console at System -> Login Management -> DLP Users. At this point you can log into the console as either of these users, with Server Management privileges.