Likely, the message you recieved looks like this:
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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 the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is(…).
Please contact your system administrator.
Add correct host key in /home/username/.ssh/known_hosts to get rid of this message.
Offending key in /home/username/.ssh/known_hosts:xx
RSA host key for lab-machine has changed and you have requested strict checking.
Host key verification failed.
You can completely delete the existing ‘known_hosts‘ file in your .ssh directory to avoid this message and log in, or as the message states, remove the offending line. The ‘known_hosts’ file will be repopulated, and a machine entry will be added each time you log in to a different machine.
rm ~/.ssh/known_hosts
You can add the correct host key containing entries of all the CADE lab machines from a file on our website, available here.
Posted in: Computational Server, FTP and SFTP, Remote Access, SSH Related, Unix