[root@zk01 ~]# ssh localhost

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

@ 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:r86jc/Vu8phhiKKDSntetfkmksjQ606ZlUP8XNYe44U.

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:10

Password authentication is disabled to avoid man-in-the-middle attacks.

Keyboard-interactive authentication is disabled to avoid man-in-the-middle attacks.

Permission denied (publickey,password,keyboard-interactive).

说明： Add correct host key in /root/.ssh/known_hosts to get rid of this message.  重点在这句话

分析： ssh登录过某机器后，因某机器有变动（更换ip等），再次登录不了，报错！！！

解决过程：

[root@zk01 ~]# mv /root/.ssh/known_hosts /root/.ssh/known_hosts.bak

[root@zk01 ~]# ssh -o StrictHostKeyChecking=no 172.16.38.130

Warning: Permanently added '172.16.38.130' (ECDSA) to the list of known hosts.

root@172.16.38.130's password:

Last login: Sun Oct 1 12:02:21 2017 from 172.16.74.104

[root@zk01 ~]# ssh localhost      ## 输入密码，OK！

Warning: Permanently added 'localhost' (ECDSA) to the list of known hosts.

root@localhost's password:

Last login: Sun Oct 1 12:04:59 2017 from zk01