Static DAC ports for named instances

Question

Using SQL 2016 Enterprise Edition

The default instance will listen on 1433 and the DAC port will listen on TCP 1434. SQL Browser will listen on UDP 1434. Any subsequent named instances will get a dynamically allocated port from windows in the range 49152 to 65535 as will their DAC ports. Connection requests (including DAC) to those named instances will make a call to SQL Browser and told the port number.

You can use the SQL Server Configuration Tool to change the port for the named instance to a static port number, but there is no option to set the DAC port to a static port number.

When I suggested to the networks team that I'd like the entire port range opened up for remote DAC connectivity, they were less than enthusiastic.

Is there any way to set the DAC port to a known, static port number for named instances?

Answer 1

Taken from the Microsoft Support site:

To configure a static port for the specialized Dedicated Administrator Connection (DAC), you must update the registry key that corresponds to your instance. For example, the registry key may be the following:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.X\MSSQLServer\SuperSocketNetLib\AdminConnection\Tcp

Note The "X" in "MSSQL.X" is a number that indicates the directory where the instance is installed for SQL Server 2005 or the instance name for SQL Server 2008.

Although the article talks about SQL Server 2008, this works for all Windows-based versions from 2005 and above. SQL Server on Linux uses a different mechanism, which I am not yet aware of.