Problem scenario
You have a server that has run SSH to connect to other servers. You want to remove the fingerprints so the ECDSA key fingerprint will challenge a user to continue connecting. What do you do?
Solution
Run this command where x.x.x.x is the IP address or hostname of the server whose finger print should be removed: ssh-keygen -R x.x.x.x
If you used a hostname with the SSH comands, use a hostname in the command above. If you used an IP address with the SSH commands, use the IP address in the command above.