Host1:

ssh-keygen
No PassPhrase (so automatic logon works)
Default filename and path is ok
cat ~/.ssh/id_rsa.pub
Copy content of id_rsa.pub

 
Host2:

Create ~/.ssh
Create ~/.ssh/authorized_keys
Paste content of clipboard into authorized_keys

 
Both steps vice vera
 
At the first logon a warning appears that the hostkey is added
to know_hosts. Yes to proceed.
 
That’s it