FAQ:

When I try to ssh into xxx system, the following message appears.

@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ 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 the RSA host key has just been changed. The fingerprint for the RSA key sent by the remote host is df:ee:b0:80:c9:f0:99:22:9f:06:77:72:d4:fa:fe:4f. Please contact your system administrator. Add correct host key in /home/rukshana/.ssh/known_hosts to get rid of this messa ge. Offending key in /home/rukshana/.ssh/known_hosts:19 RSA host key for lnx1621 has changed and you have requested strict checking. Host key verification failed. rukshana_lns131% ssh lnx1621.lns.cornell.edu The authenticity of host 'lnx1621.lns.cornell.edu (172.16.2.1)' can't be establi shed. RSA key fingerprint is df:ee:b0:80:c9:f0:99:22:9f:06:77:72:d4:fa:fe:4f. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added 'lnx1621.lns.cornell.edu' (RSA) to the list of known hosts. Warning: the RSA host key for 'lnx1621.lns.cornell.edu' differs from the key for the IP address '172.16.2.1' Offending key for IP in /home/username/.ssh/known_hosts:19

ANSWER:

Generally these messages appear if a system has been upgraded or re-installed. To stop seeing the messages, you need to remove the referenced line from ~/.ssh/known_hosts and/or /etc/ssh/ssh_known_hosts.

• To remove the offending line from your personal ~/.ssh/known_hosts file, manually edit the file or execute:

  ssh-keygen -R hostname

• To remove the offending line from the system-wide /etc/ssh/ssh_known_hosts from a CLASSE Managed linux box, please submit a ServiceRequest. Alternatively if you have root privileges, you can manully edit the file or execute:

  ssh-keygen -f /etc/ssh/ssh_known_hosts -R hostname

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