Log on with an administrator account
Open a command prompt.
Type Dsmgmt and press Enter.
Type Local Roles and press Enter.
Type Add <UserName> Administrators where <UserName> is the name of the domain account that you want to assign as a local administrator on the RODC.
Once Adam was logged in I repeated the process by trying to add a user named Aaron.Lee. Aaron was added to the local administrators group. I was also able to still log on locally with both accounts and use AD Users and Computers with both. This is in contrast to Microsoft's Documentation on the topic.
Remember, an RODC local administrator cannot manage other DCs or Active Directory. They can:
- Install hardware devices, such as network adapters and disk drives
- Manage disk drives and other devices
- Install software updates and drivers
- Stop and start Active Directory Domain Services (AD DS)
- Install and remove other server roles and features
- View logs in Event Viewer
- Manage shares and other applications and services