SQL Server driver received an unexpected pre-login response.

Trying to evaluate DbVis for MS SQL Server (2008). I am using other tools (Toad) which can connect fine but DbVis keeps spitting out "The driver received an unexpected pre-login response. Verify the connection properties and check that an instance of SQL Server is running on the host and accepting TCP/IP connections at the port. This driver can be used only with SQL Server 2000 or later." DbVisualizer Free 9.2.14 [Build #2495], OS: Windows 7 64-bit Java Version: 1.7.0 (32 bit) I used exiting Java 1.7 on my workstation when installing, although previously I allowed for local install of Java for DbVis. jTDS doesn't work at all. I've tried MS JDBC driver v3 and v4 (sqljdbc4.jar) and the above error keeps happening. Again - TCP connectivity is OK, other tools making connection from same computer, other systems connecting with the sqljdbc4.jar driver. Appears the issue is specific to DbVis.

Hi, The error message you get is from the driver and typically means that the port number or instance name is invalid: https://social.msdn.microsoft.com/Forums/sqlserver/en-US/e7886a17-d231-4ae3-99ae-f49babd5c858/jdbc-to-sql-server-2005-the-driver-received-an-unexpected-prelogin-response?forum=sqldataaccess In order to figure out what the problem may be, please create one connection using the jTDS driver and one using the MS JDBC driver and try to connect both. Then open Help->Contact Support and report the issue. We will then receive info about the connection configuration and all error messages which hopefully will let us tell you what to do. Best Regards, Hans

Indeed the port number is invalid, but apparently this is because DBVis is not using the SOCKS proxy that everything else on the system is using. When connecting with a different client I observed the SOCKS traffic and a successful connection, but when attempting to connect with DBVis, no SOCKS traffic was captured and therefore the port was not able to be reached. How could DBVis be circumventing my SOCKS client for database communication? I tried changing Tools->Tool Properties->Proxy Settings. Set to 'Use System Proxy Settings' and no success. Set to 'Use Manual Proxy Settings' and entered the local host and port on which the proxy service is running and still no success. If I simply type telnet I make a successful connection, because it goes through the proxy.

Hi, The Proxy Settings in Tool Properties are for HTTP traffic, not for database access. I assume you mean that you need to connect via an SSH Tunnel (handled by the SOCKS proxy). If so, you need configure the tunnel in the Connection tab. This is only available in the Pro edition, so you must first start an evaluation period in Help->Evaluate Pro Edition. After this, you should see an SSH Tunnel section in the Connection tab: http://confluence.dbvis.com/display/UG92/Using+an+SSH+Tunnel Best Regards, Hans

SSH Tunnel is an alternate solution in this case and does work. However, I don't see why I can't simply specify the database connection go through the SOCKS client running on my workstation. Other software does this seamlessly. Thanks for your prompt assistance.

Hi, It is the driver that establishes the connection, and it should work the same with DbVisualizer as it does with other applications that uses it. Which other software do you mean? Does it use JDBC? How the proxy configured? Do you mean the standard Windows proxy settings? If so, is it enabled for the JDBC protocol? Which Windows version do you use? Best Regards, Hans

I would say apparently nothing else is using JDBC, otherwise I'd have the same issue. This is SOCKS client software which runs as a service on Windows 7. Sounds like I will have to investigate why it is not enabled for JDBC protocol. Thanks for your help.