How To Fix Offending key in ~/.ssh/known_hosts file

How To Fix Offending key in ~/.ssh/known_hosts file

Remove the offending ssh key

Following error will be displayed when the remote host key changes (after you’ve connected earlier with a valid remote host key).

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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

a7:a8:f2:97:94:33:58:b7:9d:bc:e0:a6:6b:f7:0a:29.

Please contact your system administrator.

Add correct host key in /home/ramesh/.ssh/known_hosts to get rid of this message.

Offending key in /home/gaurav/.ssh/known_hosts: 6

Permission denied (publickey,password).

You have to remove the key to proceed further. Use the following command to remove the offending key.,

# sed -i '6d' ~/.ssh/known_hosts

Note: Change the 6d according to the line number shown.

If your sed does not have -i option, use perl or use some editor to remove the offending key.
Perl solution:

# perl -pi -e 's/\Q$_// if ($. == 6);' ~/.ssh/known_hosts

Note: Change the line number from 6 to appropriate line number.