I have 3 Application Servers and One SQL Database Server. One Application server cannot connect with SQL DB.

The 3rd server can have ports closed, it can be domain issue etc. etc.

Download PortQry and check whether all necessary posts are open on the 3rd server.

The older PortQry version offers UI.

Port opened, I am able to telnet

Portquery also resolved successfully.

As part of my troubleshooting, I found the below points.

SQL Server 2012 sp4

1. From the 3rd server "SQL Management Studio (Version 18.2)" I couldn't able to connect SQL DB.

2. Whereas from the other two application servers, from "SQL Management Studio" I can connect SQL DB.

What login type do you use? SQL login or Windows login?
What is the OS version on application servers?
Are all computers in the same domain?
What error message is reported?

check the windows firewall on the dB server and make sure the sql rule (port 1433) is allowed for the other app server ip

@Aaron How would you explain the telnet can communicate through the port?

didn’t see a specific port mentioned

What login type do you use? SQL login or Windows login?--Windows domain account.SQL Error-4.jpeg
What is the OS version on application servers?--Windows Server 2012 R2 standard
Are all computers in the same domain?--All are in the same domain only
What error message is reported? -- PFA
Firewall rule also allowed in advanced rules 1433 allowed

OK, we know this is not connection issue but permissions or compatibility issue.
If you are sure just one domain user is used on all application servers then I have no explanation and the only recommendation is to test/use SQL login.

Then you should check the SQL Server Native client version. It should correspond to the SQL Server version. This version should work: https://www.microsoft.com/en-us/download/details.aspx?id=50402

You may find the current version in Registry: https://support.microsoft.com/en-au/help/321185/how-to-determine-the-version-edition-and-update-level-of-sql-server-an

While connecting to odbc getting this errorSQL Error-5.jpeg

Still, issue not resolved.

Please find attached error and suggest.



SSL Security error could mean you have incorrect SSL setup or the driver does not support required SSL (TLS) version.
You should install newer ODBC driver, e.g. SQL13ODBC or SQL17ODBC available e.g. here: https://www.microsoft.com/en-us/download/details.aspx?id=53339

I have installed and checked, but still the same issue. Any suggestions?