背景
在安裝完openssh之後，還是不能解決登錄的問題。報錯信息如下：
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 ...
解決辦法
重新針對目標ip生成ssh文件，就會將之前舊的文件重新存成.old文件。
ssh-keygen -R <host>
接着在重新使用ssh登錄即可。