We have migrated the application databases from an old SQL Server 2000 instance running on Windows 2003 to a new SQL Server 2022 instance running on Windows 2022. The application tier has a number of web servers using IIS 6.0 on Windows 2003 and when they try to test the connection to the new SQL Server they get the below SSL security error. Any idea what could be the issue is here, is it likely to be the driver(screenshot below shows drivers installed on the web servers)? Or is it likely to be related to what versions of SSL/TLS are enabled on either side?
Windows Server 2003 only supported SSL 3.0 and TLS 1.0 if I'm remembering correctly. The client drivers from 2003 are extremely old and generally won't support later TDS changes, given the only drivers available to 2003 were for SQL 2000 at the time. IIS 6.0 only supported SSL 3.0 and TLS 1.0 as well.
Essentially you're going to need to upgrade your app servers.
Turning off encrypted connections is fine, however with the TDS protocol that old connecting to a version of SQL Server 22 years newer may work for some/most things but something will occur, not if but when.
There's no common combination (without editing the registry and enabling unsecure ciphers) of ciphers between WS2003 and WS2022, that's going to be a potential other hurdle. Hence why upgrading the app server is the best thing to do.