What to consider when replicating Active Directory

There are two main approaches when it comes to migrating Active Directory or domain controllers from a disaster:

1. Replicating the entire environment, including the AD server(s) - in this approach it is recommended to launch the drill or recovery AD servers first, wait until it's up and running and then launch the other drill or recovery instances, to make sure the AD servers are ready to authenticate them.

2. Leaving the AD server(s) in the Source environment - in this approach, the drill or recovery instances will communicate back to the AD server in the source environment and will take the source server's place in the AD automatically.

   In this case, it is important to conduct any drills using an isolated subnet in the AWS cloud, so to avoid having the drill or recovery instances communicate into the source AD server outside of a recovery.