Enable remote Dedicated Administrator Connection (DAC) in SQL Server

By default, remote connection using Dedicated Administrator Connection (DAC) is disabled. It is only available from a client on the server.

When you try to connect to a remote SQL Server that doesn't have 'remote admin connections' option enabled, you will receive the following error:

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 43 - An error occurred while obtaining the dedicated administrator connection (DAC) port. Make sure that SQL Browser is running, or check the error log for the port number.)(Microsoft SQL Server)

To enable the DAC from a remote computer in SQL Server, use the 'remote admin connections' option of sp_configure:

sp_configure 'remote admin connections', 1;

To enable remote DAC in SQL Server 2008 Management Studio:
right click on SQL Server and Select Facets:

From Facets drop down Select Surface Area Configuration, select the option 'True' for RemoteDacEnabled:

If TCP port 1434 is not available, a TCP port is dynamically assigned. When more than one instance of SQL Server is installed on a computer, check the error log for the TCP port number.

SQL Server Browser service must be running to connect to Dedicated administrator connection (DAC).

It is possible to make only one connection at a time with DAC.