Communicating with the server 2017

This part of my tests are very unexpected. I have right now openSUSE Leap 42.2 on each computers (my desktop and my server). As far as I can tell it's no more necessary to use the "-X" ssh switch to have X11 forwarding activated, so it seems to be as default. After some research (and asking to mates), it's enough to have X11 forwarding both on the server and on the client, and now looks like openSUSE gives this setup as default.
If Firefox have a running session on the desktop, and "firefox" is typed in *the server terminal*, a new windows open on the desktop (save do save on the desktop). If firefox is *not* running on the desktop, typing "firefox" opens a firefox server session that displays on the desktop, but save on the server. Option --no-remote gives the last result even if an other session of Firefox is still running on the desktop. So better use "firefox --no-remote" anyway.

test open ports with:

You can also launch xfce on the server. That is, even with an already running session on the server you can run an other as user. Log with "ssh user@serverIP" and type startxfce and you will have an xfce session starting on top of your plasma session. Last time I tried this (some years ago) doing so made my kde4 session unsusable. I didn't really test using xfce on the server like this for a long time though.