InformationThe remote admin connections option controls whether a client application on a remote computer can use the Dedicated Administrator Connection (DAC).
The Dedicated Administrator Connection (DAC) lets an administrator access a running server to execute diagnostic functions or Transact-SQL statements, or to troubleshoot problems on the server, even when the server is locked or running in an abnormal state and not responding to a SQL Server Database Engine connection. In a cluster scenario, the administrator may not actually be logged on to the same node that is currently hosting the SQL Server instance and thus is considered 'remote'. Therefore, this setting should usually be enabled (1) for SQL Server failover clusters; otherwise it should be disabled (0) which is the default.
SolutionRun the following T-SQL command on non-clustered installations:
EXECUTE sp_configure 'remote admin connections', 0;
By default, this option is disabled (0), only local connections may use the DAC.
If it's a clustered installation, it must be enabled as a clustered SQL Server cannot bind to localhost and DAC will be unavailable otherwise. Enable it for clustered installations. Disable it for standalone installations where not required.