[RndTbl] X remote login

Daryl F wyatt at escape.ca
Wed Apr 17 18:12:23 CDT 2002

On Wed, 17 Apr 2002, Gilbert E. Detillieux wrote:

> According to Sean A. Walberg:
> > On Wed, 2002-04-17 at 16:07, Ihor Jakowec wrote:
> > > I would like to login to  the University of Winnipeg's
> > > mainframe, with an X window interface, from my personal
> > > computer at home.  Up to now I have just been logging in
> > > with telnet ( in text mode).
> >
> > 2 ways come to mind
> > - SSH in from your machine to the UofWs.  X-tunneling (if they've
> > allowed it) will let you run X clients on their machines, but be
> > displayed on yours.
> That's probably the best way to do it, particularly if you're only
> interested in running a few individual X applications, launched from the
> command line, as opposed to getting the whole X login environment of the
> remote host.
> It also has the advantage of being more secure.
> > - Telnet in.  Set $DISPLAY to your ip:0.0 and then run an X client, ie
> >
> > mybox$ telnet uofw
> > blah
> > blah
> > uofw$ export DISPLAY=my.ip.address:0.0
> > uofw$ xterm &
> That's another option, of course, but a bit more tedious and error-prone.
> You'd also have to give your X server permission to accept connections from
> the remote host system, since the X clients on that host will be trying to
> connect back to your server directly.  (The beauty of the X-tunneling option
> in SSH is that's all taken care of, and each end thinks it's dealing with
> local client/server connections.)
> > Or are you looking for an XDMCP login?
> I think that's what he had in mind, as that's what had been discussed during
> the round-table discussion at the last MUUG meeting.  I know that works at
> the U of M, but the U of W may not allow XDMCP-managed connections from
> remote addresses.  (Perhaps it's not allowed for the same security reasons a
> lot of campuses are no longer allowing telnet, ftp, and other protocols that
> exchange passwords as clear text.)
> It's also possible the U of W allows it, but we don't know what host should
> be queried for XDMCP support.  Anyone from the U of W listening, who may
> know the answer?
> --
> Gilbert E. Detillieux		E-mail:	<gedetil at cs.umanitoba.ca>
> Dept. of Computer Science	Web:	http://www.cs.umanitoba.ca/~gedetil/
> University of Manitoba		Phone:	(204)474-8161
> Winnipeg, MB, CANADA  R3T 2N2	Fax:	(204)474-7609
> _______________________________________________
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> Roundtable at muug.mb.ca
> http://www.muug.mb.ca/mailman/listinfo/roundtable
  A third option that can help with the XDMCP issue is using VNC. Check
with the UofW and see if they allow you to start a VNC server on their
host and the install the VNC viewer on your computer.
  If you set up the .xstartup on the UofW host correctly you can have the
desktop you normally get on that host.
  This option is also faster than the other two. The X-windows packet
protocol is not very efficient. Unless you have extremely fast connection
you will find ssh or telnet connections cumbersome. And even with VNC it
will not be as fast as you might like. Mouse activity generates too much
discrete activity in typical X-windows applications.
  Another, ableit dubious to some, advantage is that you can get VNC
viewers for platforms other than Linux and Unix. And still get the same
desktop. I personally like having a Solaris desktop on Windows. Seems
fitting somehow :)
  You can find more information about VNC at:


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