Monday, March 26, 2012

Getting "SQL Server does not exist or access denied" error messages

For some reason, this week we started to get "SQL Server does not exist or
access denied" error messages when attempting to connect to our SQL Server
databases. This only affects people who dial into our network. But this
seems to be a rather complicated situation, so let me explain.
We have a couple of VB6 applications we've written. People log into our
network and get authenticated on our network (username, password and domain
must be specified). We have a test server with SQL Server 2000 installed.
The test server is a Windows 2000 Server. The production server has SQL
Server 2000 installed also, but it is a Windows 2003 Server. I have found,
for example, that I can define an ODBC DSN to the test database and retrieve
data just fine, but I can NOT do the same thing to the production database
on the production server. However, our users were able to do so up until
Tuesday of this week. The only thing I can think of which has changed is I
applied the 5 critical updates that Microsoft related Tuesday/Wednesday on
the DHCP server. But the DHCP server is not either the production or test
database servers, so I have no idea why that should make any difference at
all.
Does anyone have any idea why this problem is now showing up?
RodHi Rod,
If this is was fine before, then I would suspect that it is an issue related
to the security. Usually this error happens when client does not have
permissions to connect to the SQL Server. Could be that last changes in a
fixes were related to the security issues. Do you know which patches were
installed exactly. If yes, then you could check KB articles for them to see
if installation of them does not change any security settings.
--
Val Mazur
Microsoft MVP
"Rod" <Rod@.NO.SPAM> wrote in message
news:u05d8jpaEHA.4092@.TK2MSFTNGP11.phx.gbl...
> For some reason, this week we started to get "SQL Server does not exist or
> access denied" error messages when attempting to connect to our SQL Server
> databases. This only affects people who dial into our network. But this
> seems to be a rather complicated situation, so let me explain.
> We have a couple of VB6 applications we've written. People log into our
> network and get authenticated on our network (username, password and
> domain
> must be specified). We have a test server with SQL Server 2000 installed.
> The test server is a Windows 2000 Server. The production server has SQL
> Server 2000 installed also, but it is a Windows 2003 Server. I have found,
> for example, that I can define an ODBC DSN to the test database and
> retrieve
> data just fine, but I can NOT do the same thing to the production database
> on the production server. However, our users were able to do so up until
> Tuesday of this week. The only thing I can think of which has changed is I
> applied the 5 critical updates that Microsoft related Tuesday/Wednesday on
> the DHCP server. But the DHCP server is not either the production or test
> database servers, so I have no idea why that should make any difference at
> all.
> Does anyone have any idea why this problem is now showing up?
> Rod
>
>

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