Hello,

I have encountered similar error "Cannot Generate SSPI Context" it seemed from nowhere. I have read the article (and other also) and resources on microsoft site, but while trying to identify the problem in the - active directory/kerberos/name resolving - i found interesting effect. Read further.

We have SQL Server 2000 SP3 is running on the win2003 cluster, everything works fine (switching, recovery...). Authentication method is 'Mixed mode'. Users are working in the terminal with application, which uses domain user to connect to SQL Server (maybe its not very efficient, but we do not discuss that issue now).

However due to databse fragmentation the performance of application bacame very poor, many looks due to scaning indexes. So reindexing should help.

However firstly one of the fastest methods of somewhat improoving SQL Server speed is to use option "Use windows NT fibers". So I checked it and restarted server, during the night DB maintenence plan was run to reindex database tables, to further improove performance. In the morning the users started complaining that they cannot conect to the server through application. By the way, they mentioned that in the evening they also could not connect to the server from that time I have restarted server (after enabling NT fibres). Thus i turned off "Use windows NT fibers" option and restarted the server. Everything again works fine, no SSPI error 

Can someone answer the question how NT fibers are related to all these things writen about SSPI, which is somewhat as "name resolving/kerberos/active directory services" error? Because from my experience the SSPI error is directly related to enabling the option "NT fibers". As far as i understand fibers are operating system mechanizm of optimizing its work. The kerberos protocol, which is used for authentication/ticket granting/etc is also operating system integrated, but it issues the commands to OS kernel, and only after that OS organizes the threads and fibers to plan the processor time. So if we would look at the win2003 OS as a simplified hierarchical structure, I would see the following picture: 

I can not figure out why all these SSPI errors were generated?

P.S. Index defragmentation helped, DB is performing sufficiently, for now