SQL SERVER: How to open DAC (Dedicated Administrator Connection) to SQL Server Management Studio (SSMS)

DAC connection is used to SQL Server when you are not able to connect SQL Server.

Only one DAC connection is allowed for SQL Server instance.

1. Open the SQL Server Management Studio as Administrator
2. Click on “Database Engine Query” (icon next to New Query) on the toolbar.
3. In the “Server Name” box enter the server name in the following formatADMIN:local
4. Connect the server and execute the required commands.

For more details check the technet article.