How to remove or update a single entry from the SSH known_hosts file
The SSH known_hosts file contains fingerprints (generated from the remote machines SSH key) of the known machines you've logged into. If you SSH into a machine for the first time, you will be asked if you want to save that hosts' fingerprint. Consider this file your personal SSH certificate authority. One reason this file is important is that it might prevent you from logging in to a different machine with the same IP address. Say, for example, someone has compromised one of the servers on your network. You've previously logged in to that machine with SSH, but the hackers have re-directed the IP address to another machine. Should that happen, and you attempt to log into the machine with the same IP address, SSH will fail because of a mismatch on the SSH keys.
How to remove or update a single entry from the SSH known_hosts file
TechRepublic published a tutorial about how to remove or update a single entry from the SSH known_hosts file.
