Someone is doing something abnormal

If you need to log in to another Linux host, you may not be able to log in to another Linux host. If you need to log in to another Linux host, you may not be able to log in to another Linux host.
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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 is36:68:a6:e6:43:34:6b:82:d7:f4:df:1f:c2:e7:37:cc.Please contact your system Administrator.Add correct host key in /u/xlian008/.ssh/known_hosts to get rid of this message.Offending Key in /u/xlian008/.ssh/known_hosts:2RSA host key for 135.1.35.130 has changed and you have requested strict checking.Host key verification failed.
Strange, so I studied it. SSH records the public keys of every computer you visit in ~/.ssh/known_hosts. OpenSSH checks the public key the next time you access the same computer. If the public key is different, OpenSSH will warn you to protect you from attacks like DNS Hijack. The case I listed above, that’s the case.
Because there are multiple Linux systems on a single host, they will be switched frequently. If these systems use the same IP, SSH information will be recorded in the local ~/.ssh/known_hsots file after logging in. If SSH is used to access this host after switching the system, there will be a conflict warning, and the contents in known_hsots need to be deleted manually.
There are two solutions:

    to manually delete and modify known_hsots; Change the configuration file “~/.ssh/config”, add these two lines, and restart the server.
    StrictHostKeyChecking no
    UserKnownHostsFile /dev/null

The advantages and disadvantages:

    needs to manually delete the contents of the file each time, some automated scripts cannot run (failed when SSH login), but the security is high; Known_hsots access is ignored when SSH logs in, but the security is low;


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