Can anyone give me some basic pointers and tips on ssh? (Specific questions at end.) Background. In the process of trying to compare and contrast the configuration differences across three different Linux laptops in my home--this in order to try to figure why one of them consistently fails to connect to imap.comcast.net (continuing saga; not what I wish to address here)--it occurred to me that I might be able to ssh from one computer into the others in order to see and copy certain portions of the different directory structures into a text file on my desktop. This so that I could study everything in a convenient, organized fashion in one place (again not the topic at issue; but, yes, I'm not the kind of person who can memorize a phone book.) Sure enough! I can ssh into Debian machine from Kubuntu machine. I can ssh into Debian machine from Ubuntu Mate machine. But connections are refused from Debian machine into Kubuntu and Ubuntu Mate and between Kubuntu and Ubuntu Mate machines. If I remember correctly, when I setup the Debian machine I opted to install a server. But that was months ago and I haven't thought it about since, nor do I even know where to find it. Does it boot with the machine and make itself available so that I can ssh into it? I don't know. Old as I am I'm still a server-side noob, barely a twinkle in my Daddy's eye. All I know about servers is that I've watched some videos and installed a couple of Ubuntu Server virtual machines for trying to learn some basics about understanding and managing networks and servers (became interested mostly because of the longtime foggy notion that I'd like to someday get a Raspberry Pi and setup a PiHole to work with our router; again, not the issue at hand, just more background for those of you who know me.) I've used ssh at the most basic level about half a dozen times in my life. So my questions are: 1. Is it not possible to ssh from the machine you are typing at into the target/host machine without having a server installed and running on the target machine? Are there permissions or shares or ports or whatnot that need to be configured on the target machines? To the best of my knowledge there are no firewalls running on the machines. 2. Where might general ssh learning time be best spent first? Any good cheat sheets or overviews to recommend? (Yes, I know what man pages are, and even how to use them passably well if I have a clear concept of what it is I'm supposed to be looking for.) Thanks, Tom