I have seen lots of questions floating in the msdn forums about SSPI Handshake error, the main question is around error code 0x80090311 which is indicative of the authentication failure error. Apart from this, there are many other reasons for SSPI Handshake error to appear in error logs.
SSPI is an abbreviation Security Support Provider Interface, is an API that sends data back and forth until the security provider is satisfied. That means, when a user tries to connect to a SQL Server machine using Windows Authentication, as soon as user clicks login but a security token has been generated for that particular client and is sent to the AD/Authority system to validate the token once it has been authenticated successfully it allows user to login and access the system. Here is the link for further reading on SSPI
In some cases this failed and there could be multiple reasons for this, they could be anything, including:
Microsoft has made a KB article on how to troubleshoot SSPI Error available to fix this issue. However, I would like to give you some more links for reference:
Hope this helps.
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