A fully functional ssh installation that works reliably under 12.1 has stopped working after upgrading to 13.1. (The good news is I still have the HDD with 12.1 on it)
Using netstat, sshd is listening on 22 and 23 and sshd shows up in ps auxwww | grep sshd. The config file is the same one from 12.1. In short, there should be some degree of function. When I try to establish a connection either by local, same-net IP address or via a dynamic URL (verified with ping), the result is “connection timed out”. There’s no hint of attempting to authenticate the connection. Something changed but I don’t know what.
Right now, what I’d like (barring the answer to the whole mess) is a pointer to how to diagnose where the problem occurs. The material I turn up with Google is about authentication; I’m not even to the point of seeing a “nobody I know - bye!” message.