Trusted Access Versus Nontrusted Access

As you can see, you can lock down access to SQL Server to the “nth” degree. Why then does the support for Mixed Mode linger? For starters, backward compatibility with earlier versions of SQL Server is a good reason. Second, if you have a remote SQL Server 2005 system, on a secure WAN segment, or anywhere for that matter, and it sits in a nontrusted domain, or as a stand-alone server on a non-Windows network, there is no means of presenting client authentication in the network communication. In other words, the connection cannot raise a Security Support Provider Interface (SSPI) to the SQL Server. This means that the only way to gain access is to transmit the internal user ID and password pair to SQL Server for access.