Thank you for reaching us!
I understand that you would like to know the impact of rebooting the Entra connect server.
If you restart the Entra Connect server, the synchronization process will be interrupted and will resume automatically once the server is back online. The synchronization process will resume from where it left off before the server was restarted. A temporary delay in the synchronization of changes between your on-premises Active Directory and Entra ID it will depend on the size of your environment and the number of changes that are being synchronized at the time of the restart.
Hope this helps. Do let us know if you any further queries by responding in the comments section.
Thanks,
Akhilesh.
If this answers your query, do click Accept Answer
and Yes
for was this answer helpful. And, if you have any further query do let us know.