SQL Server Login Auditing can be used to monitor login activities on SQL Server Database Engine. SQL Server can log both failed and successful login attempts on the server. It provides four different options for Login Auditing.

1. None – No Login activity is logged,

2. Failed logins only – Only failed attempts to login to SQL Server are logged,

3. Successful logins only – Only successful logins are logged,

4. Both failed and successful logins – Both successful and failed attempts are logged.

To configure these options you can use Management Studio, Go to Server Properties > Security Tab:

A Server restart is required when you change these options.

These logged event can be viewed using Event Viewer:

1. Open Event Viewer

2. Go to Windows Logs > Application,

3. Both Logon success and failure events can be found here:

Hope This Helps! Cheers!