vic can probably do it if you use multicast locally;
http://mediatools.cs.ucl.ac.uk/nets/mmedia/
but that is probably whole new kettle of fish.
On Tue, 5 May 2009, William Shu wrote:
> Dear All,
> I think I now have a clearer approach to finding solutions to some of my problems. the suggestions of Stephen, Troy and Miles were particularly helpful.
>
> First, the the solutions obtained so far:
> enabling Xforwarding and restarting daemons (e.g., sshd) permits me to have trouble-free displays over ssh or from xterm windows of different users on the same console.
>
> From the help offered, I think my solution strategy for multi-terminal display could be one of the following:
> 1) Bring up vnc display, have a "master vnc viewer" that can read/write on the display, and let all the other vnc viewers be "slave vnc viewers" that can only view the display. Unfortunately, blocking keyboard/mouse actions using the options menu from pressing the F8 key can be reset by the user. An suggestions to configure vnc to have such master-slave viewers?
>
> 2) Create a separate account, which can possibly become insecure by granting xauth authorities, and use vnc to display whatever. While the implications of extending access (via xauth) frighten, the use of a video conferencing tool, such as EVO, seem to require internet access, whereas the machines I'll use are in a closed LAN. Does anyone know of a video conferencing tool that does not register to/through the internet?
>
> Once more thank you all for the support.
>
> William.
>
>
> --- On Tue, 5/5/09, Stephen J. Gowdy <[log in to unmask]> wrote:
> From: Stephen J. Gowdy <[log in to unmask]>
> Subject: Re: Problems using X Windows Display
> To: "William Shu" <[log in to unmask]>
> Cc: "Miles O'Neal" <[log in to unmask]>, [log in to unmask]
> Date: Tuesday, May 5, 2009, 7:44 AM
>
> On Mon, 4 May 2009, William Shu wrote:
>
>>
>> Thank you very much Miles!
>>
>> I rebooted both machines and I can now view pdf/ *.ps files without
> complaints!
>>
>> vncviewer now opens on the host machine when invoked from the remote
> machine through ssh. However, I have the following three problems (whose
> solutions I guess will help end this thread):
>>
>> 1) Everything has suddenly become so slow on the host machine (I think);
> shortly after opening the vnc window seems to freeze, not displaying X clients,
> though the window itself can be reduced or expanded!
>
> Sorry, no idea there.
>
>> 2) Trying to open vnc without ssh complains of no route to host (error
> 113). Also, xclock complains of inability to open display.
>
> This is probably your firewall preventing access as I mentinoed. Looking at it
> I think you need to open 5901 on your server. I've never used though so
> I'm not sure.
>
>> 3) Related to (2) above, it seems I can only project X disply on another
> terminal through ssh, which requires login (and hence knowing another user's
> password). Is there no other secure way of doing this, where the target user can
> selectively authorise the display?
>
> Each user could have an account on the host machine that is different.
> They'd all need to know the shared password for the VNC server though.
> Probably not a good idea.
>
> You can use xauth as described before to allow a user to do everything with
> your X session either via an ssh tunnel or directly if you open port 6000
> (assuming your display is :0) on your firewall. However, something like EVO
> would be a much safer way to share a desktop window. There are probably other
> applications that would do it too.
>
>>
>> The following outputs show what transpired:
>>
>> [wss@hpsl5 ~]$ ssh -XY [log in to unmask]
>> [log in to unmask] password:
>> Last login: Tue May 5 02:57:19 2009
>> [wss@inteksl52 ~]$ echo $DISPLAY
>> localhost:10.0
>> [1]+ Done evince
> Desktop/semanticKnowledge-a4-geissler.pdf
>> [wss@inteksl52 ~]$ vncviewer &
>> [1] 6612
>> [wss@inteksl52 ~]$
>> VNC Viewer Free Edition 4.1.2 for X - built Feb 11 2009 12:55:24
>> Copyright (C) 2002-2005 RealVNC Ltd.
>> See http://www.realvnc.com for information on VNC.
>>
>> Tue May 5 03:08:35 2009
>> CConn: connected to host localhost port 5901
>> CConnection: Server supports RFB protocol version 3.8
>> CConnection: Using RFB protocol version 3.8
>>
>> Tue May 5 03:08:54 2009
>> TXImage: Using default colormap and visual, TrueColor, depth 24.
>> CConn: Using pixel format depth 6 (8bpp) rgb222
>> CConn: Using ZRLE encoding
>>
>> Tue May 5 03:18:27 2009
>> main: End of stream
>>
>> [1]+ Done vncviewer
>> [wss@inteksl52 ~]$
>>
>> <... snip ...>
>>
>> [wss@hpsl5 ~]$ vncviewer 192.168.10.20:1 &
>> [1] 3888
>> [wss@hpsl5 ~]$
>> VNC Viewer Free Edition 4.1.2 for X - built Feb 11 2009 12:55:24
>> Copyright (C) 2002-2005 RealVNC Ltd.
>> See http://www.realvnc.com for information on VNC.
>>
>> Tue May 5 03:38:32 2009
>> main: unable to connect to host: No route to host (113)
>>
>> [1]+ Exit 1 vncviewer 192.168.10.20:1
>> [wss@hpsl5 ~]$
>> [wss@hpsl5 ~]$ xclock -display 192.168.10.20:1 &
>> [1] 5564
>> [wss@hpsl5 ~]$ Error: Can't open display: 192.168.10.20:1
>>
>> --- On Tue, 5/5/09, Miles O'Neal <[log in to unmask]> wrote:
>> From: Miles O'Neal <[log in to unmask]>
>> Subject: Re: Problems using X Windows Display
>> To: [log in to unmask]
>> Date: Tuesday, May 5, 2009, 1:02 AM
>>
>> William Shu said...
>>
>> |Xforwarding:
>> |------------
>> |Changed the Xforwarding to yes in /etc/ssh/sshd_config of remote mach=
>> |ine (inteksl52):
>> |
>> |#X11Forwarding no
>> |X11Forwarding yes
>>
>> Did you restart the ssh daemon after that change?
>>
>>
>>
>>
>>
>>
>
> -- /------------------------------------+-------------------------\
> |Stephen J. Gowdy | CERN Office: 8-1-11|
> |http://cern.ch/gowdy/ | CH-1211 Geneva 23 |
> | | Switzerland |
> |EMail: [log in to unmask] | Tel: +41 76 487 2215 |
> \------------------------------------+-------------------------/
>
>
>
>
>
>
--
/------------------------------------+-------------------------\
|Stephen J. Gowdy | CERN Office: 8-1-11|
|http://cern.ch/gowdy/ | CH-1211 Geneva 23 |
| | Switzerland |
|EMail: [log in to unmask] | Tel: +41 76 487 2215 |
\------------------------------------+-------------------------/
|
