From: rich@example.invalid   
      
   Harold Johanssen  wrote:   
   > On Sat, 22 Oct 2022 14:49:11 -0000 (UTC), Rich wrote:   
   >   
   >> Harold Johanssen  wrote:   
   >>>        I don't think I have explained my situation properly.  My   
   >>> apologies.  Let me try again:   
   >>>   
   >>>        Host A is running an XFCE session that was launched in A   
   >>> with vncserver :1, vncserver being the TigerVNC X server.   
   >>   
   >> Ok, that 'fine point' did not come across well in the original post.   
   >>   
   >> Is The TigerVNC X server listening on a TCP port for remote X   
   >> connections?  Because if it is not, then you can't just do   
   >> "DISPLAY=*" on B and have apps on B connect to A (because to connect   
   >> to A, something on A has to be listening on the proper TCP port on   
   >> A).   
   >   
   >        It is.  In fact, I can connect to it from anywhere (as long as   
   > there is ssh conectivity) with ssvnc - which, in essence, just   
   > tunnels vncviewer through an ssh channel.   
      
   Connecting via vncviewer is different than a direct xlib connect.  You   
   are trying to do native X11 xlib TCP connections, which are not   
   vncviwer connections.  However, this does mean both systems /can/ see   
   each other over the network.   
      
   >> If the TigerVNC server does not listen for remote X connections on a   
   >> TCP port on A, then this will not work.   
   >   
   >        I does.   
      
   Are you sure it is listening for xlib raw X11 TCP connections?  It may   
   only be listening for vncviewer connects, which are not the same.   
      
   >> Instead, try using ssh X forwarding (the -X or -Y options) which tunnel   
   >> the X protocol over the ssh connection, and which cause ssh to setup the   
   >> proper DISPLAY variable on B for you automatically.   
   >   
   >        I tried with ForwardX11=yes in .ssh/config in both systems, to no   
   > avail. At any rate, I had no need for that when the XFCE session in A was   
   > launched over Xorg, rather than TigerVNC.   
      
   With xorg, you had xorg listening on TCP 6000 for raw X11 xlib TCP   
   connections.  Unless TigerVNC also listens on port 6000 for raw X11   
   xlib TCP connections, you'll get exactly the error message you are   
   seeing.   
      
   >>>        The thing is, until recently I had an XFCE session running   
   >>> on A directly on top of Xorg, not TigerVNC's Xvnc - and the steps   
   >>> above worked as expected.   
   >>   
   >> Likely because the real xorg was listening on a TCP port for remote   
   >> X connects (usually TCP 6000).  The TigerVNC server may not provide   
   >> such support at all, or it may be a CLI option to TigerVNC to cause   
   >> it to turn on "listen for external connections".   
   >   
   >        Thanks.  I am confused about something here thoug: when I said   
   > above that I can vncviewer into A from B, the ports involved in A are   
   > (I believe) 5900 and above - in my case, 5901, I think.   
      
   5900+ are the default for vnc connections.   
      
   > Are you saying that, besides this, the X server (TigerVNC, in my   
   > case) must be listening on port 6000 as well for what I am trying to   
   > do to succeed?   
      
   Yes, the default for raw xlib network connections is TCP 6000.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)