SSPI Handshake errors

My initial purpose for this blog was to post things that caused me trouble at work that I could not find answers to what I was looking for on google. One of the things that has cropped up lately is some SSPI handshake errors for users connecting to a central SQL Server. The first most obvious cause of this that I have found is when a user has a basic change in their active directory user account. Sometimes their account gets locked out from too many failed password attempts or they change their password, and until this replicates to all sites, they can get handshake errors. Failing that the event log usually shows evidence of issues communicating with servers in regards to these issues. The best resource I have found when troubleshooting this issue is the sql protocols blog. There is one specific page that I can't seem to find again that has several different scenarios where this can occur and how to troubleshoot it. I think one of the keys to this is understanding Kerberos.