Configuration Manager install failed with “A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online”

Installing Configuration Manager 2002 failed at Database Information with the following error message –

UDL with SQL Server Native Client showed the following message –

The client and server cannot communicate, because they do not posses a common algorithm. Client unable to establish connection Encryption not supported on the client

ConfigMgrSetup.log has such messages –

04-07-2021 11:28:13.230 Configuration Manager Setup 5404 (0x151c) *** [08001][21][Microsoft][SQL Server Native Client 11.0]Encryption not supported on the client.
04-07-2021 11:28:13.230 Configuration Manager Setup 5404 (0x151c) *** [08001][-2146893007][Microsoft][SQL Server Native Client 11.0]SSL Provider: The client and server cannot communicate, because they do not possess a common algorithm.~~
04-07-2021 11:28:13.230 Configuration Manager Setup 5404 (0x151c) *** [08001][21][Microsoft][SQL Server Native Client 11.0]Client unable to establish connection
04-07-2021 11:28:13.230 Configuration Manager Setup 5404 (0x151c) *** [08001][-2146893007][Microsoft][SQL Server Native Client 11.0]A network-related or instance-specific error has occurred while establishing a connection to SQL Server. Server is not found or not accessible. Check if instance name is correct and if SQL Server is configured to allow remote connections. For more information see SQL Server Books Online.

The fact is that SQL Server 2019 is ready on a separate server. Both the SQL server and SCCM server have the same SSL capabilities(IISCRYPTO is a good free tool that gives administrators the ability to enable or disable protocols, ciphers, hashes and key exchange algorithms on Windows Server 2008, 2012, 2016 and 2019). What is the problem then?

It turned out that on SCCM server SQL Server Native Client version, which is 11.0.2100.60, is too low.

Per the official guide, the minimum version is SQL Server 2012 SP4 (11.*.7001.0). The final solution is to upgrade SQL Server Native Client to the supported version. You can download it here –

Download Microsoft® SQL Server® 2012 Native Client – QFE from Official Microsoft Download Center

References

• Prerequisite checks – Configuration Manager | Microsoft Docs
• Download Microsoft® SQL Server® 2012 Native Client – QFE from Official Microsoft Download Center
• Prerequisite checks – Configuration Manager | Microsoft Docs