How to add untrusted domain controllers to a collection (4246715)

1. On the left-hand pane, right-click the "Active Directory" node and click "Connect to Forest".

2. Fill out either the target forest FQDN, or a target DC FQDN, as well as a username and password valid for that forest.
If this fails to connect, make sure that the target DC and Domain name can be resolved by the RMAD Server.

3. Once connected, navigate to "All Domain Controllers", right-click the DC you want to add to a collection and click "Add to Collection".

4. In the window that pops up, either choose an existing collection or create a new one. 
You will need to configure the collection to send remote credentials, so untrusted forests should have their own collection.

5. Once you have added the DC(s), expand Collections, and select the collection that you added it to to confirm.