Tom ... The semantics break down. Not sure I'll do any better, but here goes! Client and server terminology is often reversed in X speak. I'll repeat this below. And a lot of this you know already.
VNC gives you what-appears-to-be a bitmapped display. X clients connect to that. But there's no physical display, hence the "V" in VNC stands for virtual. (Not in the v-memory sense.) While Linux on a PC will have any of several X servers (because it can have any of several physical bitmapped displays) Linux on S/390 will *only* have the VNC X server. But that may NOT be what they want. When your users mention CYGWIN, clearly they're after X (server) on Windows boxes with XDMCP access to your Linux host(s). Strictly speaking, X on Linux is then the CLIENT, even though the host is considered to be a server. CYGWIN XFree86, like other X-on-Windows, will use the XDMCP protocol to establish a session. But the server (the X server) is on the PC, not on the mainframe (nor on the remote PC). Still, they will get a sign-on effect as if their PC were the client. And in sign-on semantics, it is the client. Client and server terminology is often reversed in X speak. VNC gives you an X server, yes! The X server in VNC is local to your zSeries Linux system. With VNC, the X traffic does not flow across the network. To connect a display to the VNC X server, you must use a 'vncviewer', as you already have. So the VNC server is a server in two senses: X and VNC. You know a lot of this already. Sorry. I don't mean to insult you. Sounds like they don't want to go the VNCVIEWER route. Oh well. If they're running CYGWIN XFree86 (or any other X-on-Windows) then the X traffic does flow across the network, not VNC traffic. If you cannot get them to use VNC, then you *can* enable XDM on the Linux system. There will be no bit-mapped display so the config is a little confusing at first. But it is no different from a headless Sun playing the XDM (XDMCP) game. (Or a headless RS/6K or a headless HP or a ... you get the idea.) I hope this helps. -- R;
