For the most part, the default port for SSH access into a Linux machine is 22. However, many people change this default in the name of security, meaning that for most of our function usage, we simply need to use the -p port number switch when trying to access with that remote machine.
However, interestingly enough, the -p switch was never bundled with the useful ssh-copy-id function, meaning that should you try something like this:
ssh-copy-id -p221 -i ~/.ssh/id_rsa.pub username@host
you will get a reply back reading: Bad port ‘umask 077; test -d .ssh || mkdir .ssh ‘ cat >> .ssh/authorized_keys’.
Not exactly encouraging.
However, there is actually a simply way to fix this and use ssh-copy-id when interacting with a non-default port 22 machine. Simply enclose your port declaration together with the host name within quotation marks!
So the correct usage would now look like this:
ssh-copy-id -i ~/.ssh/id_rsa.pub ‘-p 221 username@host’
And damn it, it actually works! Nice.