From the machine that you wish to connect from, run the command below with the user that you will connect with to the remote machine:
In my example of command below; The user used was root.
run this command:
ssh-keygen -t dsa
From there you can run this command, replace remote_IP with the remote machine’s IP.
cat /root/.ssh/id_dsa.pub | ssh root@remote_IP 'cat >> /etc/ssh/keys-root/authorized_keys'
Next time, no password would be asked to gain access.