Manually adding a host SSH fingerprint into known_hosts

I noticed that when connecting to a non-standard port for SSH e.g. host.com:2020 that the SSH host fingerprint was not being added to the users known_hosts file. So in order to perform this manually we should issue:

ssh-keygen -p 2020 host.com

host.com ssh-rsa AAAABBBBBBCCCCCC.....

and then append it to our known_hosts

echo AAAABBBBBBCCCCCC..... >> ~/.ssh/known_hosts