SSH

connect to server

ssh server
ssh username@server
ssh -p port username@server

Set public key authentication
- create key on local

ssh-keygen

- make sure the server hv .ssh dir. if not create it

 ssh-keygen

- copy the local public key to server

scp ~/.ssh/id_rsa.pub remote.server.com:.ssh/authorized_keys2

- now login it without password