This error is reported on a server with SQL Server installed :
SSPI handshake failed with error code 0x8009030c while establishing a connection with integrated security; the connection has been closed. [CLIENT: xxxxxxxxxx]
Based on experience, this error occurs under different circumstances and can be tricky to diagnose. I’ve had to troubleshoot and issue various corrective mesaures:
1) If a Windows service account is used and the password changes. This is a common reason.
2) The SPNs are invalid. An SPN is the Server Principal Name utilized by Kerberos authentication. In that case , delete the MSSQL SVC SPN and issue a SQL Server restart. This registers immediately.
3)Rights have been denied , analyse the local security policies.
Try running gpresult. Gpresult displays the Group Policy Settings and Resultant Set of Policy (RSOP) for the server. It should also tell you any problems/errors that it found when processing the GPOs.
4)Check communications with AD .
5) Is the server recognised?