I have a Web server in my DMZ, I have a SQL Server 2008 R2 server inside the LAN, this database server has named instance with a NO dynamic port. I have set as firewall rules the connection from my DMZ server and the database server in the SQL Server instance port and the UDP port 1434 for SQL Browser.

I thought this will be enough to allow the connection between the two servers, however I created a UDL file in my DMZ server and tried to connect to the SQL server instance and it failed, but when I included the Instance port in the string, it worked.

Please can you help me, I want to be able to connect to the named instance without including the Instance port, instead use the SQL Browser as it would be for other serves inside the LAN.


  • Do you have another SQL Server instance running on the server?
    – benRollag
    Commented Jul 28, 2012 at 22:55

1 Answer 1


Although what you described should work as configured, another option would be just create an alias for your named instance.

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