>If the SQL Server is ready to accept connections on port 1433, why is the above connection request trying to go to 139? That port is typically blocked on servers that aren't running a file or printer sharing role.

Well, that is what I am trying to figure out. We have a Web server and a SQL Server. In that event viewer log, the source is the Web server and the destination is the SQL server. So, the only think I can see is the ASP.NET SQL client data provider trying to establish a communication with the database. So, even if port 1433 is open. Another port is trying to get used and that causes a problem.

>For testing purposes it can be helpful to replace the server name with its IP address. This can eliminate a possible network lookup to resolve a name to an IP address.

It is already an IP address. I just changed it in here to hide it from the conversation.

>You may also be able to specify the port explicitly e.g. http://www.connectionstrings.com/sqlconnection/connect-via-an-ip-address/

I'll check that. Thanks