ssh:known-hosts:remove

The command ssh-keygen -R ${hostname} is used to remove a specific host key from the known_hosts file in SSH. Here is a breakdown of the command:

• ssh-keygen: This is the command-line tool for managing SSH keys.
• -R: This option specifies that we want to remove a host key from the known_hosts file.
• ${hostname}: This is a placeholder for the actual hostname that you want to remove from the known_hosts file. You need to replace ${hostname} with the specific hostname you want to remove.

When you run this command, it will remove the host key entry for the specified hostname from the known_hosts file. This can be useful when you encounter a warning about a changed or unknown host key when connecting to an SSH server, and you want to remove the old key to avoid further warnings.

Note: Be cautious when using this command, as removing the host key of a remote server can potentially make you vulnerable to man-in-the-middle attacks if the server's identity has indeed changed.