Event ID - 1645

Event Id1645
SourceActive Directory
DescriptionThe Directory Service received a failure while trying to perform an authenticated RPC call to another Domain Controller. The failure is that the desired Service Principal Name (SPN) is not registered on the target server. The server being contacted is %1. The SPN being used is %2. Please verify that the names of the target server and domain are correct. Please also verify that the SPN is registered on the computer account object for the target server on the KDC servicing the request. If the target server has been recently promoted- it will be necessary for knowledge of this computers identity to replicate to the KDC before this computer can be authenticated.
Event InformationAccording to Microsoft:
EXPLANATION:
Active Directory did not perform an authenticated remote procedure call (RPC) to another domain controller because the desired service principal name (SPN) for the destination domain controller is not registered on the Key Distribution Center (KDC) domain controller that resolves the SPN.
USER ACTION:
Verify that the names of the destination domain controller and domain are correct. Also, verify that the SPN is registered on the KDC domain controller. If the destination domain controller has been recently promoted, it will be necessary for the local domain controller’s computer account data to replicate to the KDC before this computer can be authenticated.
Reference LinksWindows Operating System (Active Directory)

Catch threats immediately

We work side-by-side with you to rapidly detect cyberthreats
and thwart attacks before they cause damage.

See what we caught

Did this information help you to resolve the problem?

Yes: My problem was resolved.
No: The information was not helpful / Partially helpful.