SPN’s (Service Principal Names)
Having problems authenticating? Maybe you need an SPN?
Here is some information on SPN’s (Service Principal Names), but basically SPN’s allow a client to find a service for Kerberos authentication.
SPN information from MSDN
http://msdn2.microsoft.com/en-us/library/ms677949.aspx
SPN information from TechNet
http://technet2.microsoft.com/windowsserver/en/library/b3a029a1-7ff0-4f6f-87d2-f2e70294a5761033.mspx
SPN information from SQL Server Docs
http://msdn2.microsoft.com/en-us/library/ms191153.aspx