or, What have the latest windows 2003 service pack 2 has done to my sql server ?
Today i scheduled for my self some working time on the NightDuck project (Coming Soon),
but suddenly something went wrong, the sql server, which installed on a physically different machine than the development rig, gave me the following message:
"Sql server does not exist or access denied ConnectionOpen(Connect())"
what could have go wrong ?
the interesting part is when i tried to connect to the server remotely (remote desktop) and connecting to the Sql server from the localhost, it had no problems what so ever.
Since the sql server machine is not a dependency of a production application or something like that, i went wild on the experiments to try and fix the problem
- Lets restart the sql server service - no good.
- Router configurations and port forwarding - nothing has changed since the last time i worked on the project, thats not the problem either
- SQL SERVER user - defining a new user did not solved the problem either
so i started googling on the subject, and found a few things, like this one for example at the Microsoft site :
Potential causes of the "SQL Server does not exist or access denied" error message
this article has a list of things that may cause this problem (hard to guess by it's name).
checking the relevant ones, i came across this article about ports needed by the sql server.
i made a little test to check if the ports are ok, i tried to telnet the machine from the dev PC on the 1433 port, but with no luck,
in an effort to isolate the problem i tried that from the localhost of the server, telneting to the localhost on port 1433, which gave me an error "could not connect...".
this is what i was looking for !
At this point the problem is completely isolated, why ?
- the router configuration is not an issue (request does not go out from the machine)
- the development rig is not part of the equation anymore
- firewall is not the problem
based on these symptoms, I've searched once more, and stumbled upon a forum thread about a very similar issue, when installing service pack 2 on windows XP causes the same effect.
Apparently, if you have an out of date version of the file DBNETLIB.dll ,the Service Pack 2 disables TCP/IP access to MS SQL Server.
This is a defense against the Slammer worm. (some ugly work around by Microsoft a have to say...)
the solution is installing the SQL Server 200 security tools , which sets things back to normal.
since the windows 2003 service pack 2 is quite new, i guess this thread will be useful
update :
Just wondering how many others encountered this specific problem,
if you find this info useful, please leave a comment.