今天重置服务器后，连接出现以下错误
# Host 123.56.221.254 found: line 1
/var/root/.ssh/known_hosts updated.
Original contents retained as /var/root/.ssh/known_hosts.old
MacBookdeMacBook-Pro:~ macbook$ ssh [email protected]
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ 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 a host key has just been changed.
The fingerprint for the ECDSA key sent by the remote host is
SHA256:lT6FPZDEww/DmyoPTxfUTI4rn17rTHWTncxCFWzavco.
Please contact your system administrator.
Add correct host key in /Users/macbook/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /Users/macbook/.ssh/known_hosts:12
ECDSA host key for 123.56.221.254 has changed and you have requested strict checking.
Host key verification failed.
问题在于：第一次SSH连接时，会生成一个本地密钥，储存在客户端的known_hosts中，每次登陆时候该密钥验证。
重置系统之后生成新的密钥，导致本地的旧密钥不匹配服务端的新密钥
步骤如下：
1， 进入路径 cd ~/.ssh
2， 进入文件 vim known_hosts
3， 删除 known_hosts里面关于 对应云服务器IP 的信息，保存退出即可