1. 情景描述

 电脑首次通过终端成功连接Linux设备后；更换设备，但IP不变，进行终端连接时产生如下报错：

bash
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    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
SHA256:83EVp2xxxxxxxq2T1673aikbbi2Gh4sxxxxxxxxxx.
Please contact your system administrator.
Add correct host key in /Users/xxxx/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /Users/xxxx/.ssh/known_hosts:13
Host key for [192.168.55.78]:3719 has changed and you have requested strict checking.
Host key verification failed.

2. 解决

1. 报错含义

bash
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

 我的 ~/.ssh/known_hosts 文件中，记录了 IP 192.168.55.78（端口 3719）的旧的公钥 fingerprint（指纹），但目标主机现在给你发送了一个新的公钥，因此 SSH 报出警告，担心是被篡改或中间人攻击。

bash
The fingerprint for the ECDSA key sent by the remote host is
SHA256:83EVp2xxxxxxxq2T1673aikbbi2Gh4sxxxxxxxxxx.

Add correct host key in /Users/xxxx/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /Users/xxxx/.ssh/known_hosts:13
Host key for [192.168.55.78]:3719 has changed and you have requested strict checking.
Host key verification failed.

• known_hosts:13 表示这个主机的旧密钥在你本地 known_hosts 文件的第 13 行
• fingerprint 是远程服务器发来的公钥指纹
• SSH 默认开启了 StrictHostKeyChecking，所以不允许自动接受新的 key

2. 常见原因

3. 解决方法：用文本编辑器打开并手动删除对应行

bash
nano ~/.ssh/known_hosts

 执行后会自动从 ~/.ssh/known_hosts 中删除对应行。然后再次连接：

bash
ssh -p 3719 [username]@192.168.55.78

 你会看到提示：

bash
Are you sure you want to continue connecting (yes/no/[fingerprint])?

 输入 yes 后会将新的 key 加入到 known_hosts 文件中。