(python)pmitros@lm2:~/distributed-classroom$ ssh pmitros@machine.org
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@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
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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 RSA key sent by the remote host is
e3:7b:76:92:f5:ca:52:17:39:94:a4:0a:ba:b0:ef:23.
Please contact your system administrator.
Add correct host key in /home/pmitros/.ssh/known_hosts to get rid of this message.
Offending ECDSA key in /home/pmitros/.ssh/known_hosts:18
  remove with: ssh-keygen -f "/home/pmitros/.ssh/known_hosts" -R machine.org
RSA host key for machine.org has changed and you have requested strict checking.
Host key verification failed.
(python)pmitros@lm2:~/distributed-classroom$ ssh-keygen -f "/home/pmitros/.ssh/known_hosts" -R machine.org
/home/pmitros/.ssh/known_hosts updated.
Original contents retained as /home/pmitros/.ssh/known_hosts.old
(python)pmitros@lm2:~/distributed-classroom$ ssh pmitros@machine.org
The authenticity of host 'machine.org (18.999.999.999)' can't be established.
RSA key fingerprint is e3:7b:76:92:f5:ca:52:17:39:94:a4:0a:ba:b0:ef:23.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'machine.org' (RSA) to the list of known hosts.
Warning: the RSA host key for 'machine.org' differs from the key for the IP address '18.999.999.999'
Offending key for IP in /home/pmitros/.ssh/known_hosts:34