Answer - A nonauthoritative restore is the default method for restoring Active Directory. To perform a nonauthoritative restore, you must be able to start the domain controller in Directory Services Restore Mode. After you restore the domain controller from backup, replication partners use the standard replication protocols to update Active Directory and associated information on the restored domain controller. An authoritative restore brings a domain or a container back to the state it was in at the time of backup and overwrites all changes made since the backup. If you do not want to replicate the changes that have been made subsequent to the last backup operation, you must perform an authoritative restore. In this one needs to stop the inbound replication first before performing the An authoritative restore.