If you are experiencing an error message saying that the OpenSSH server daemon has failed to start, there are a few potential causes for this issue. Here are some steps you can take to troubleshoot the problem:

1.Check the error message: The error message may provide some clues as to what is causing the issue. Look for any specific error codes or messages that may help identify the problem.

2.Check the SSH configuration file: The OpenSSH server configuration file is typically located at /etc/ssh/sshd_config. Check to see if the file has any syntax errors or incorrect settings that may be preventing the server daemon from starting.

3.Check system logs: The system logs may contain additional information about the problem. You can check the system logs by running the command sudo journalctl -u sshd on a Linux system.

4.Check for conflicting services: Make sure there are no other services running on the same port as the OpenSSH server. The default port for OpenSSH is 22, so check to see if any other services are using this port.

5.Restart the SSH service: Sometimes simply restarting the SSH service can resolve the issue. You can do this by running the command sudo systemctl restart sshd.

6.Reinstall OpenSSH: If all else fails, you may need to reinstall OpenSSH on your system. This can be done using your system’s package manager (e.g. apt on Ubuntu, yum on CentOS).
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1. Failed to start the ssh server

2. Check the failure reason

3. Solutions