"Connection to the linked server has failed" error after you update Windows Server
This article helps you resolve errors that occur when a connection to the linked server fails after the recent Windows Server updates are installed.
Symptoms
The following error messages are logged in the SQL Server error log.
TCP Provider: An existing connection was forcibly closed by the remote host.
OLE DB provider "MSOLEDBSQL" for linked server "<LinkedServerName>" returned message "Client unable to establish connection". (Microsoft SQL Server, Error: 10054)
The following screenshot shows the event ID 36874. This is a Schannel error that occurs in the Windows Event Viewer which indicates that the client and server support different sets of cipher suites which causes a failure in connection.
Cause
The ciphers for the SQL Server client and server were modified after you installed Windows Server updates. As a result, there were issues with communication.
How to check cipher values
To check the cipher values on the client and server computers, follow these steps:
Open an administrative PowerShell session, and then run the following command on both the client and main server:
Get-ItemPropertyValue -Path HKLM:\System\CurrentControlSet\Control\Cryptography\Configuration\Local\SSL\00010002\ -Name Functions
Compare the values from both computers to determine whether the ciphers differ.
Resolution
To resolve the problem, follow these steps:
If a network trace isn't available, check the functions value in this registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Cryptography\Configuration\Local\SSL\00010002
Run the following PowerShell command to find the Transport Layer Security (TLS) functions:
Get-ItemPropertyValue -Path HKLM:\System\CurrentControlSet\Control\Cryptography\Configuration\Local\SSL\00010002\ -Name Functions
Use the Ciphers Suites tab in the IIS Crypto tool to check whether there are any matching algorithms. If no matching algorithms are found, contact Microsoft Support.
Third-party contact disclaimer
Microsoft provides third-party contact information to help you find additional information about this topic. This contact information may change without notice. Microsoft does not guarantee the accuracy of third-party contact information.
See also
An existing connection was forcibly closed by the remote host (OS error 10054)