There are 2 Linux hosts: 001 and 002. User 'tuyendq' wants to ssh login from 001 to 002 without entering password.
Generate ssh key pair on 001 host
[tuyendq@001 ~]$ ssh-keygen -t rsa
Remotely create ~/.ssh directory on 002 host
[tuyendq@001 ~]$ ssh tuyendq@002.practicehabits.net mkdir -p .ssh
Remotely append .ssh/id_rsa.pub file content to .ssh/authorized_keys file on 002 host
[tuyendq@001 ~]$ cat .ssh/id_rsa.pub | ssh tuyendq@002.practicehabits.net 'cat >> .ssh/authorized_keys'
Try ssh from 001 host to 002 host without enter password
[tuyendq@001 ~]$ ssh tuyendq@002.practicehabits.net
$ exit Connection to 002.practicehabits.net closed. [tuyendq@001 ~]$
Host key verification failed
C:\Users\Tuyen>ssh 192.168.64.141 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ 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:mad5gNQXpUJ0Iro8Ycfz7+AUsm7+mqEyxSlL8Ro6FqU. Please contact your system administrator. Add correct host key in C:\\Users\\Tuyen/.ssh/known_hosts to get rid of this message. Offending ECDSA key in C:\\Users\\Tuyen/.ssh/known_hosts:10 ECDSA host key for 192.168.64.141 has changed and you have requested strict checking. Host key verification failed.
One way to remove line 10 from known_hosts file
C:\Users\Tuyen>ssh-keygen -R 192.168.64.141 # Host 192.168.64.141 found: line 10 C:\Users\Tuyen/.ssh/known_hosts updated. Original contents retained as C:\Users\Tuyen/.ssh/known_hosts.old C:\Users\Tuyen>ssh 192.168.64.141 The authenticity of host '192.168.64.141 (192.168.64.141)' can't be established. ECDSA key fingerprint is SHA256:mad5gNQXpUJ0Iro8Ycfz7+AUsm7+mqEyxSlL8Ro6FqU. Are you sure you want to continue connecting (yes/no)?
Another way to remove line 10 from known_hosts file
C:\Users\Tuyen>sed -i '10d' .ssh/known_hosts