Ssh

sudo nano /etc/sshd_config

ssh-keygen -t ecdsa -b 521

ssh-copy-id -i ~/.ssh/id_ecdsa.pub someuser@192.168.1.42

or

ssh-copy-id -i ~/.ssh/id_ecdsa.pub -p 1234 someuser@192.168.1.42

ssh-keygen -t ecdsa -b 521

ssh -p 1234 someone@192.168.1.44

I stumbled across this...need to test it out:

Just define your non-standard ssh ports in ~/.ssh/config file like so:

Host 192.168.1.103
Port 1431

Now all ssh based tools will just work without any extra command line hassle.

Error resolution

ERROR:

ssh_exchange_identification: Connection closed by remote host

Resolution:

server error. rebooted.