[GLLUG] Questions about Cygwin/XFree86 - ports and SSH tunneling

[Matt Shirilla]

I finally had a chance to use setup Cygwin/XFree86.  Paul is correct in his
assertion - It does rock.  The display panel on my Linux install is of poor
quality and using VNC only made matters worse.  With a Cygwin/Xfree86
session from my W2K computer I get much higher quality display, I was not
expecting that.

I created a XDMCP session between my W2K and Linux computers.  Here are the
results of a netstat on my Windows box.
192.168.80.86:6000     192.168.80.9:32776     ESTABLISHED
192.168.80.86:6000     192.168.80.9:32789     ESTABLISHED
192.168.80.86:6000     192.168.80.9:32790     ESTABLISHED
192.168.80.86:6000     192.168.80.9:32794     TIME_WAIT
192.168.80.86:6000     192.168.80.9:32795     ESTABLISHED
192.168.80.86:6000     192.168.80.9:32796     ESTABLISHED
192.168.80.86:6000     192.168.80.9:32797     ESTABLISHED
192.168.80.86:6000     192.168.80.9:32798     ESTABLISHED
192.168.80.86:6000     192.168.80.9:32799     ESTABLISHED
192.168.80.86:6000     192.168.80.9:32800     ESTABLISHED
192.168.80.86:6000     192.168.80.9:32805     ESTABLISHED
192.168.80.86:6000     192.168.80.9:32808     ESTABLISHED

Why so many connections?

I would like to use Putty to tunnel the XDMCP session.  Is there a good
guide for this?


>-----Original Message-----
>From: Melson, Paul [mailto:PMelson at sequoianet.com]
>Sent: Tuesday, October 28, 2003 4:58 PM
>Cc: linux-user at egr.msu.edu
>Subject: RE: [GLLUG] Red Hat, VNC, and remote displays (was: 
>no subject)
>
>
>I'm afraid I have disagree with you here.  In both cases, you have a
>client and a server.  There are some differences in the way 
>that VNC and
>X11 handle redraw areas and color, but in the end, the X 
>'server' or the
>VNC client are both just displaying a bitmap on the local machine and
>the application being viewed is using resources on the remote machine.
>
>The pro's and con's of each are different.  X11 is much more flexible.
>But it's a bandwidth pig, and can have problems with color 
>maps.  VNC is
>JAPCAC (just another PC/Anywhere clone), but it's a lot more remote
>access-friendly.  It also works with more operating systems.  For
>instance, you can view a WinXP desktop via VNC.  Can't do that 
>with X11.
>:-)  There's even a WinCE client.  
>
>PaulM
>
>PS - I'd like to shamelessly plug XFree86 for Cygwin.  It 
>rocks.  Remote
>apps or not.  I recently got the latest fluxbox-devel to compile along
>with a couple of dock-apps.  For those who can't stand WindowMaker (or
>can't stand waiting for KDE on Cygwin to load), I highly recommend it,
>and would love to help anyone that wants get it up and 
>running.  I would
>say that I probably work 30-40% in XFree86 on Cygwin.
>
>
>PPS - Here is a little tidbit I sent around the office on getting VNC
>working w/ XDMCP logins for RedHat 9.  This will look familiar to SuSE
>users:
>
>Thought some of you guys might find this useful.  Sorta like Terminal
>Services for RedHat, only not. :-)
>
>RedHat package requirements:
>xinetd
>vnc-server
>[ all of the default GNOME/X11 stuff ]
>
>
>1st, edit /etc/services and add the following line:
>
>vnc-login     5942/tcp     XDM-style login for VNC
>
>
>2nd, create the file /etc/xinetd.d/vnc and add the following:
>service vnc-login
>{
>        socket_type     = stream
>        protocol        = tcp
>        wait            = no
>        user            = nobody
>        server          = /usr/bin/Xvnc
>        server_args     = :42 -inetd -once -query localhost -geometry
>800x600 -depth 16
>        type            = UNLISTED
>        port            = 5942
>}
>
>5942 was randomly picked just so that it's not 5900-5910 where default
>VNC listeners often are.  It has no significance other than it must be
>the same here and in /etc/services.
>
>
>3rd, restart xinetd (`/etc/init.d/xinetd.d restart`)
>
>
>4th, edit /etc/X11/gdm/gdm.conf
>
>Find the line containing "[xdmcp]" and the line below it:
>
>Enable=false
>
>Change "false" to "true" and save.
>
>
>5th, restart gdm (`killall -HUP gdm-binary`), but be nice and let the
>person at the console log off first.
>
>
>6th, connect to "hostname:42" using the VNC client of your choice.
>
>
>It tunnels well via SSH for security, too:
>
>ssh -fN user at linxbox -L 5942:127.0.0.1:5942 && vncviewer localhost:42
>
>
>Change "-depth 16" to "-depth 8" in /etc/xinetd.d/vnc for slower
>connections where 256 colors can do the job.
>
>
>-----Original Message-----
>Thus, the amount of network traffic being generated is highly dependent
>on the nature of the application, and X and VNC both generate different
>kinds of traffic. Some applications might fare well with X and others
>may feel more responsive with VNC. Some might perform horribly on both.
>:)
>
>
>I've always been tempted to try out the Cygwin XFree86 server, 
>but since
>my workstation is a FreeBSD machine, I rarely need to display X
>applications on a Windows, machine. Much more common is the reverse. :)
>Although I'd like to experiment with thin clients running off a central
>application server in the near future, so maybe the opportunity will
>arise.
>
>
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