ssh:... Connection refused

Recently, I installed Leap 15.6 on one of my two computers and gave it the name "azure", "az" and the IP address 192.168.2.17. Then, from my other computer, which still carries Leap 15.2, I tried to reach it by the command "ssh az", getting the error message: "ssh: connect to host az port 22: Connection refused" Analogous error messages I get for "ssh azure" and "ssh 192.168.2.17", as to be expected. I have already checked the .ssh root and user directories and /etc/ssh on both of my computers, not finding anything wrong. What else can I do for getting ssh access to my computer "az"? Thanks in advance and best regards, Wolfgang