Difficulty: Hard
Correct Answer: Boot one DC into Directory Services Restore Mode, restore System State with Windows Backup, run NTDSUTIL to mark objects authoritative, then restart
Explanation:
Introduction / Context:When erroneous directory changes replicate to all domain controllers (DCs), a simple non-authoritative restore will be overwritten by newer, bad data. An authoritative restore is required so the restored DC's directory data is treated as the newest and is replicated out to other DCs, effectively rolling back the domain to the prior backup state.
Given Data / Assumptions:
Concept / Approach:An authoritative restore consists of: 1) booting into Directory Services Restore Mode (DSRM) so AD is offline, 2) restoring System State (which contains ntds.dit, SYSVOL, registry), and 3) using ntdsutil to mark the restored directory data authoritative (update version numbers/USNs). On reboot, the restored DC's data replicates to the others, undoing the unwanted changes.
Step-by-Step Solution:
On a chosen DC, press F8 > Directory Services Restore Mode and log on with the DSRM password.Run Windows Backup and restore the previous day's System State.Launch ntdsutil > authoritative restore, and mark the needed objects/containers or entire database authoritative.Restart normally to allow replication to propagate the authoritative data to other DCs.Verification / Alternative check:Inspect event logs for replication status and validate corrected user accounts/attributes. Use repadmin to confirm healthy replication.
Why Other Options Are Wrong:
Common Pitfalls:Forgetting to restore the correct backup set or not isolating the DC during restore can re-import bad changes; ensure you use DSRM and authoritative flags.
Final Answer:Boot one DC into Directory Services Restore Mode, restore System State with Windows Backup, run NTDSUTIL to mark objects authoritative, then restart
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