The DAC allows an dba to access a SQL Server to troubleshoot problems. You can connect using either SQLCMD or SSMS.
DAC is working with port 1434 to allow client connection from Remote computers
To enable DAC for a remote computer,
sp_configure 'remote admin connections', 1;
In the Connect to Database Engine dialog box, in the Server name box, type ADMIN: followed by the name of the server instance. For example, to connect to a server instance named UKDEVSQL\HRMS,