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@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
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IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that a host key has just been changed.
The fingerprint for the ECDSA key sent by the remote host is
SHA256:a9lEA2txpLhsQ2eDcqLgOE7TFyWzJaGTxOpimS0r36M.
Please contact your system administrator.
Add correct host key in /Users/wxl/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /Users/wxl/.ssh/known_hosts:31
ECDSA host key for 8.142.33.16 has changed and you have requested strict checking.
Host key verification failed.

使用ssh root@192.23.22.333 连接服务器，报如上错误，经过查找资料发现可以通过清理known_hosts文件内容恢复正常，也可以直接删除该文件。