Desktop Background?

[xytsrm]

I've installed UltraVNC on two XP machines, and have it functioning successfully within my network, remotely via my router, as well as remotely through my router's VPN tunnel.

However, I've noticed that when I connect to a target machine the desktop background is not displayed - only the standard blue background. If I go into the desktop properties and re-select the background it displays, but only as long as the connection is maintained. When I disconnect and re-connect the background is gone. Is this normal, (ie. saving bandwidth) or is something setup incorrectly?

X.

[Rudi De Vos]

server option [] disable background

[mattice06082]

There's an UltraVNC Admin Properties option for "Remove Wallpaper for Viewers" which is selected by default.

[xytsrm]

Rudi De Vos - I was not able to find any option under properties, or admin-properties called "disable background".

Mattice - I tried unchecking "Remove Wallpaper for Viewers"; it did not make any difference - the blue background still displayed when I connected.

Any other suggestions .

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[mattice06082]

I just tried it out on one of my machines and it took a system restart to take effect. Deselecting the option didn't take effect by disconnecting and reconnecting. It also didn't take effect after simply restarting the service. Only after I rebooted the UltraVNC server system did the background appear. I'm not a developer so I can't explain why, but that's how it worked here.

[xytsrm]

Thanks Mattice,

I'm not at my home location now, but I'll give that a try when I get there.

I appreciate the help.

Maybe, you could help me with another minor problem. To connect in remotely I've had to set the scope of the VNC5900/VNC5800 to "any IP address". I wanted to restrict this to only the locations I connect from. At a remote location my PC is assigned 192.168.1.xx, where the xx is usually 66. In the custom scope setup (in addition to my own local subnet), I entered 192.168.1.0\255.255.255.0 for the remote location. It works when I'm local, but it still won't connect when I'm remote. Any ideas as to what I might try to cover the remote location?

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[xytsrm]

Mattice,

You were right, after I re-booted the home PC, the Viewer displayed the desktop wallpaper. I also think I know why a re-boot is necessary.

I arrived home and checked the PC, it was properly in the screen-saver. However, when I logged-in I found that the Wallpaper on the PC itself was missing (Blue). I brought up the properties and noted that in fact the Wallpaper was still selected, just clicking "Ok" (exiting the properties), brought the image back.

What I believe is happening is the capability, in the VNC server, to affect the display of the Wallpaper is actually a system parameter. With the "Remove Wallpaper" checked, connecting to the server the first time turns the Wallpaper off, not for the viewer, but for the PC. Further, when the client disconnects, the backgrond is not switched back on; this is why it was off when I logged-in to the PC itself. While affecting the Wallpaper can be controlled dynamically, by the server, because the CAPABILITY to control the background is a system parameter, turning the CAPABILITY off requires a re-boot. Perhaps, the problem was disclosed because I broke the connection by simple closing the viewer-window, instead of clicking on the disconnect button; maybe the button disconnect will re-activate the normal screen display.

At least I think that's what's going on.

X.

[mattice06082]

Maybe, you could help me with another minor problem. To connect in remotely I've had to set the scope of the VNC5900/VNC5800 to "any IP address". I wanted to restrict this to only the locations I connect from. At a remote location my PC is assigned 192.168.1.xx, where the xx is usually 66. In the custom scope setup (in addition to my own local subnet), I entered 192.168.1.0\255.255.255.0 for the remote location. It works when I'm local, but it still won't connect when I'm remote. Any ideas as to what I might try to cover the remote location?

That makes sense. 192.168.1.66 is a local IP address so everyone on the same LAN knows about it. However when connecting using the WAN, the two separate private IPs don't have any knowledge of each other. You should try adding the public IP address (one that shows up when visiting http://whatsmyip.org/). Problem is that if it's dynamic then you may be locking yourself out when the IP address changes. You could try setting up a free account at http://www.dyndns.com/ and using it to set up a hostname for the location you'd be running the viewer and then use the hostname in the custom scope setup. I've never used the custom scope so I don't know if it allows hostnames, but it's worth a shot.

[xytsrm]

Thanks again Mattice,

I'll check out dyndns.

I thought that even though the remote PC is assigned a given IP it's, as you say, isolated behind the remote router, most probably it is the IP of the remote router that's being passed to the uVNC server. I can find out that public IP through the site www.grc.com, like "Whatsmyip" it will show the public IP, but more then that it's a great site to check your vulnerability when it can see the PC IP - checkout the "Shields Up" service). I'm also going to try some experiments with Wireshark to see what's actually being passed between the client and the server.



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[mattice06082]

I love Steve Gibson. Listened to every one of his Security Now! podcasts or netcasts as Leo likes to say and purchased a site license for SpinRite at my company. GRC also offers a port probe that is suggested all the time on this forum to see if a port has been properly forwarded on a router and isn't blocked by security software.

[xytsrm]

Yeah, I didn't think something like GRC would go undiscovered. I found the site 6-8 years ago, and have recomended to to many since.