公司一台服务器重做了系统，结果ssh的时候报了错误：
[root@xxx opt]# ssh xx.xx.xx.xx -p 22
WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!
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 the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
b5:38:c1:3d:1c:bb:ee:8e:72:b9:3f:9c:ca:d2:3e:ec.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending key in /root/.ssh/known_hosts:222
RSA host key for 10.1.9.161 has changed and you have requested strict checking.
Host key verification failed.
解决方法：
vi /root/.ssh/known_hosts
删掉重做的机器IP 再SSH 就没问题了。