# 別PCからサーバー（例示ではufuso.dip.jp）にrootで接続する場合のみ
[tu@ufuso ~]$ sudo ssh root@ufuso.dip.jp

[sudo] tu のパスワード: ← ユーザー（例示ではtu）のパスワードを入力（画面
に表示はされない）

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@    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:g5URH77jmdQLLLSTwm/48HZlxFVKA2a/pMUAPajMoeE.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /root/.ssh/known_hosts:1
ECDSA host key for ufuso.dip.jp has changed and you have requested strict checking.
Host key verification failed. ← サーバーに接続しているPCの暗号キーが
サーバーと合わないので接続できず

#上記の解決方法として現在の暗号キーを削除
[tu@ufuso ~]$ sudo rm -fr /root/.ssh/known_hosts

#別PCからサーバー（例示ではufuso.dip.jp）にrootで再度接続
[tu@ufuso ~]$ sudo ssh root@ufuso.dip.jp
The authenticity of host 'ufuso.dip.jp (192.168.24.241)' can't be established.
ECDSA key fingerprint is SHA256:g5URH77jmdQLLLSTwm/48HZlxFVKA2a/pMUAPajMoeE.
ECDSA key fingerprint is MD5:61:95:b0:ef:57:10:56:cc:d1:26:bf:ae:74:9b:78:4c.
Are you sure you want to continue connecting (yes/no)? yes ← yesと入力
Warning: Permanently added 'ufuso.dip.jp,192.168.24.241' (ECDSA) to the list of known hosts.

root@ufuso.dip.jp's password: ← rootのパスワードを入力（画面に表示はされない）
Last failed login: Sun Oct 29 20:11:07 JST 2017 from 192.168.24.240 on ssh:notty
There was 1 failed login attempt since the last successful login. ← ログイン成功
Last login: Sun Oct 29 19:46:34 2017