In MSSQL Server Management Studio, right-click on the server and select Properties. Choose the Security page and you will get the dialog box as below. You can select the options for login auditing as
• None – Disable the login auditing
• Failed logins – Audit for only those unsuccessful login attempts
• Successful logins only – Audit for all successful login
• Both failed and successful logins – Audit all unsuccessful and successful logins
You can get the log at the Management > SQL Server Logs.
You can do the filtering based on the Source to only list the logins entries.
