remote admin connections Option
Microsoft SQL Server 2005 provides a dedicated administrator connection (DAC). The DAC lets an administrator access a running server in order to execute diagnostic functions or Transact-SQL statements, or troubleshoot problems on the server, even when the server is locked or running in an abnormal state and not responding to a Database Engine connection. By default, the DAC is only available from a client on the server. Use the remote admin connections option of sp_configure to allow client applications on remote computers to use the DAC.
By default the DAC only listens on the loop-back IP address (127.0.0.1), port 1434.
Possible values of the remote admin connections setting:
0 - indicates only local connections are allowed using the DAC
1 - indicates remote connections are allowed using the DAC
The following code enables the DAC from a remote computer.
sp_configure 'remote admin connections', 1; GO RECONFIGURE; GO