Process Information:A pre-authentication is just the process used to verify credentials prior to returning a token. There should still be a failure audit on the server attempting authentication which includes the process id. Not straightforward even though you see the id and try to run netstat or task mgr in the system as the id changes...we need to pinpoint if the system is the same one and may be will confirm via the account being lockout using Microsoft’s own LockoutStatus.exe.
Process ID: 0x2a4
Process Name: C:\Windows\System32\services.exe
see if we have more info in sharepoint events for security error. Have the account for admin been reset before or expired or recently changed...
Logon events record the process attempting logon. Enable failed logon auditing (Security Settings > Local Policies > Audit Policy > Audit Logon Events) in the Local Security Policy (secpol.msc) then look in the security event log for an event. You can also enable it via Group Policy, if that would be preferable.
There will be a Process Information section which records both the executable path and process ID.
Usually this is when the Administrator has used the SetSPN on different accounts in an effort to get Kerberos Authentication to work. One great example of this is MS SQL. If you install MS SQL as an Administrator of the domain, it will add the MSSQLSVC SPN to the SQL Server’s computer account; later an Administrator changes the SQL Service startup account from Local System to a domain account and Kerberos Authentication starts to fail. Usually we will find that the MSSQLSVC SPN is configured on both the computer account as well as the domain user account that is used to run the service.It has a follow up in Part 3 on proper Kerberos SPN configuration. It uses a QuerySPN.vbs script to find out what account(s) have the "http/webapp" or "http/webapp.fabrikam.com"
So we will use the QuerySPN.vbs script again to find out what account(s) have the http/webapp or http/webapp.fabrikam.com SPN defined. Review KB321044 if these tools are new to you.https://blogs.technet.microsoft.com/askds/2008/06/11/kerberos-authentication-problems-service-principal-name-spn-issues-part-3/
As you can see the SPN is on the Web Server computer account. Well, this will just not work; we will need to take it off of this account and add it to the FABRIKAM\KerbSvc account using SetSPN.
NOTE: If we would have found that there were no duplicate SPN’s and that the only SPN registered in the Active Directory forest was correct we would have looked into a possible Active Directory Replication problem that might be causing the issue. You might be asking how could AD replication be causing the issue?