SQL Server does not exist or access denied error

Question

I have an application that runs fine when executed off the server. When clients try to connect, they receive the following error:

Failed to get data. *Data provider could not be initialized *SQL Server does not exist, or access denied

on my Office Web Components (MDAC). I am guessing there is some security or server configuration error, but I'm not able to pinpoint it. I am running SQL Server 2005.

*Note - clients can't change their security settings, company policy.

Answer 1

When you try this from a command prompt:

TELNET servername 1433

What happens? If you get a blank screen, then SQL Server is listening and you've got something wrong in your client settings. If you get an "Access denied" or "no response"-type answer, it's most likely either a firewall issue or SQL Server isn't listening, but in either case, it's a server issue.

Answer 2

Most likely an issue with your firewall not allowing remote connections?

Answer 3

For SQL Server to be contactable from a network machine it requires port 1433 to be open on the server for TCP traffic. Additionally, if you have a named instance you should check the port it is listening on as it may be different to the the default and will probably need to be opened. You will also have to open up port 1434 for UDP to support the SQL Browser Service

Answer 4

Your firewall settings might be preventing connections from your clients. If not, it can be a DNS issue.

Answer 5

If it's working from the server but clients are having problems, I think the "access denied" part of the error is the key here and it's an authentication problem.

What sort of authentication are you using to authenticate your clients? Is the server using impersonation? If you're running clients and server in an active directory domain, the client application (Office or Internet Explorer for example) might be passing credentials to the server which the server is using to authenticate to the database.

Answer 6

SQL Server 2005 disables network accessibility by default, you might need to enable it

http://msdn.microsoft.com/en-us/library/ms165647(SQL.90).aspx