SQLServer authentication

SQLServer supports both Windows authentication mode and mixed mode authentication mode.

Classification:

Windows authentication mode and mixed mode

Platform:

Windows

Nature:

Authentication mode

The differences between the two authentication modes are:

(1) Windows authentication mode

Only Windows authentication is performed. Users cannot specify SQL Server 2000 to log on to ID. This is the default authentication mode for SQL Server 2000. Windows authentication mode cannot be specified for SQL Server instances running on Windows 98 because this operating system does not support Windows authentication.

(2) mixed mode

If a user provides a SQL Server 2000 login ID when logging in, the system authenticates it using SQL Server authentication. If you do not provide a SQL Server 2000 login ID or request Windows authentication, authenticate it using Windows authentication.

These modes are specified during installation or using SQL Server Enterprise Manager.

Compared to SQL Server authentication, Windows authentication has some advantages, mainly due to its integration with Windows NT 4.0 and Windows 2000 security systems. Windows NT 4.0 and Windows 2000 security systems provide additional features such as security authentication and password encryption, auditing, password expiration, minimum password length, and locking accounts after multiple login requests are invalid.

Because Windows NT 4.0 and Windows 2000 users and groups are maintained only by Windows NT 4.0 or Windows 2000, when a user connects, SQL Server reads information about the user's membership in the group. If changes are made to the access rights of connected users, these changes will take effect the next time the user connects to an instance of SQL Server or logs in to Windows NT 4.0 or Windows 2000, depending on the type of change.

Description: Windows authentication mode is not available when the SQL Server instance is running on Windows 98 or Microsoft Windows Millennium.