Communication link failure

[Laneyh]

I support time & billing software which sits on a SQL database, connecting via ODBC.
Currently one of our client's is experiencing errors when trying to update timesheets over
their WAN.

When trying to submit timesheets they recieve a Red Hand error saying 'Communication Link Failure'.

The problem looks to be related to SQL connectivity but any advice on how
to investigate this would be appreciated.

They are working with SQL2000 SP4

I have advised them to check whether they are using connection pooling.

 

[NoCoolHandle]

For lack of any better error description..

if you are having a conectivity issue and you are using odbc, what happens if you go to the odbc./datasources management tool on the client (control panel or admin tools depending on system) and see if you can click the test connection button.

That should give you a better idea as to why you aren't connecting.

Other things you can do.

SLQ server comes with makepipe and readpipe (install disk). These can be good lightweight tools for testing connections.

As well as osql.

YOu might also want to make sure that the servers havn't changed security modes. (I am guessing that your application has a hardcoded user of sa and no password) if you don't allow for sql security then your app probably wont connect.

Also Great tool - in the sql program group find profiler/sql trace.

Open a trace and then try to connect from one of your clients. This should give you detailed connection attempt data and errors.

HTH


Rob

 

[Catadmin]

Use the usual network tools (Ping, PathPing, TraceRt) to make sure you have a network connection from the client box to the server. If the answer is no, the network is the problem, not the SQL Server.

If the answer is yes, next thing to check is software changes. Was anything installed/altered on either box. Is the client running Win XP SP 2 (which turns on a firewall that automatically blocks port 1433) or did the SQL Server port get changed...

Check logins and permissions also.



Catadmin - MCDBA, MCSA
"If a person is Microsoft Certified, does that mean that Microsoft pays the bills for the funny white jackets that tie in the back???