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rbees 03-19-2009 08:46 AM

ultravnc not updating host in timely manner
Ladies & Gentlemen,

I have a screen refresh issue on the remote machine.

My setup, the ultravnc-server is running on vista home on a laptop. I am accessing it form a debian squeeze laptop. I use the service to monitor my children's activities on the laptop. The connection is wireless and passing through a linux firewall but not restricted by the firewall.

I am able to login to the vista laptop fine and the screen is very responsive to the input form the linux laptop and with the two setting beside each other you wouldn't know that the input is coming in over the network.

The display on the linux laptop however takes about 10 seconds to update so much of what the child is doing is hidden. I have tried installing the video driver in vista and that didn't help.

I have also observed the same behavior when accessing the vista laptop form a desktop running xp using both ultra-vncviewer and a generic vncviewer.

Accessing the xp desktop form the linux laptop results in proper update speeds. The xp desktop is using ultra-vncserver too. Accessing the linux laptop from the vista laptop results in proper update speeds.

So it seams that this is a problem related only to screen updates coming form the vista laptop. I am pretty sure that this is a vista problem and not relevant to this forum but I have yet to find any real help from the windows world.:confused: Thought someone here might be able to shed some light on the cause:D or even better yet a fix/workaround.

I have updated the vista lappy to the most recent version of ultravnc. My son has a network widget on his desktop and it only show traffic when the update happens.

Any ideas on how I might address this issue?

Thanks to all.

jeff_k 03-21-2009 06:46 PM

Are you aware that ultravnc has its own forum? I'd recommend that you submit this there, unless you already have to no avail. Can you run a vnc client on the xp machine and get good response to the vista machine -- that would at least help isolate the problem to a vista--linux interface rather than just a vista--anything interface. There is a "backward compatible" or "run in xp compatible mode", something like that, that you might try on the vista server. I think to try to solve a strictly windoze problem, however, this thread may get booted off this forum (I mean, the moderator's name is win32sux!):)

rbees 03-21-2009 09:30 PM

Thanks jeff k

Yea I already tried their forum and it was no help. No responses at all. I don't think it gets much traffic.

Any way I have the problem fixed. There were several problems combined to cause my problem. First the instruction are not clear about how to install the drivers. You would think after using linux this long I would take a better look with more thought at them. So I didn't have the video hook drivers installed at all. After that I began to make some real success.

I did discover for those who may stumble on this that "windows ie in protected mode" really messes with the response time. I am not sure just what it was that I changed in the setup on the vista lappy that fixed it but all the problems were with the config on the vista lappy. For a while I had good response as long as ie was not running, but as soon as it started it was the same problem (worse at times).

Like I said I am not sure what i changed in the ultravnc setup that fixed the problem. I did not make any changes to vista it's self.

The only thing that is not as I would like it is that the screen flickers on the vista lappy pretty good when I connect to or disconnect from it. That means that it is known and if my children are observant they will know I am looking. I would rather it was not that way. So far I have not found a fix for it. I have also read that it may not be legal to remove that flicker. Still it is my network and I am responsible for the data that is transmitted on it.

To reiterate, I had checked to see if it was specific to the interaction between the vista lappy and linux and it was and wasn't. The problem only existed when coming form the vista laptop, the screen updates were bad no matter what, linux or xp was accessing it, and it was not a problem going the other way, the updates were proper coming from a linux server to the vista lappy.

All config problem were with the vista lappy.

Thanks anyway.

jeff_k 03-22-2009 01:43 PM

I know this isn't exactly on topic, but since your primary goal is to monitor your childrens' network activity, from one parent to another, I'll go off on a slight tangent (and put it on a more linux subject at the same time);).

I use a linux server as my router for my network; the internet is connected via one NIC, and the internal network is connected via another. This way, every packet from any of my kids' computers passes through my linux firewall on its way to the internet. Therefore, I have the ability to do significant monitoring and statistics of their web activity. Although I don't as yet take full advantage of this, my kids don't know. If you use linux, you are already well ahead of the curve in PC expertise -- I don't know if you have your kids beat, but I suspect you do. What my kids don't know won't hurt them --
I tell them that Dad is able to know about everything they do online, so don't be trying to do anything you know you shouldn't. A few things that are relatively low-tech, like having the same linux server be the DNS for the network and making opendns be the outside server address, prevents them from automatically being able to view porn sites, etc.

I'd suggest that vnc monitoring be only one aspect of your approach to keeping them safe. I am also an advocate of "trust but verify peridoically" as well. Hope this helps.

rbees 03-22-2009 03:31 PM


I already have a linux firewall/dns box between my local network and the internet. My problem there is learning how to interpret the logs. Right now I am working on setting up my third generation firewall. This one is going to be headless, there again learning how to configure all the hardening and monitoring apps takes awhile.

It is not just porn sites that concern me. If my child begins to get involved with some kind of radical extremist people I want to know. Or some other thing I don't know about yet. There are lots of things that would concern me if my child began to look into them. Still a list of ip's for "porn" and other less than reputable site would be a good thing to have. Then I could add them to the blocked add servers that I already have. I don't suppose that you know where I might get a start to some such list? I have not searched for one. My sons are pretty trustworthy.

I caught the oldist one looking at porn one day some years ago now. The wife and I had left to go to town but forgot something. So we came back and when I came in the house they didn't know I was there. That is when I caught him. He lost the use of his computer, and he spent good money on it, for awhile. Then it was in the living room where he couldn't hide what he was doing for a real long time. Interesting that I have never had any problems with the younger. Maybe he is just better at hiding it, but I don't think so.

I use to be able to convince them that I knew everything they did, whether online or just around the house. They out grew believing that when they got in high school. By the time I get so I can really monitor through the firewall they will be out on their own.

jeff_k 03-22-2009 08:06 PM

I use dnsmasq on my linux router server box. It can be configured to provide both the local dns lookup and caching, and also be your dhcp for your network. For a home LAN, it is ideal, because it is easy to configure and is still quite flexible. You can add a blacklist of websites, and also set it up to do popup blocking. Someone is maintaining a website that does a pretty good job of keeping ahead of the websites.
Go to the main website here:
Blocking ad sites using dnsmasq howto is here:
I didn't find specifically a porn blocking how-to using dnsmasq, but I am sure they are around.

If you point your dns to the nameservers at it automatically redirects when an attempt is made to a porn site. Although it is straightforward to bypass it, at least you can set it up so it is not convenient to view porn sites. Check it out -- it is probably the easiest thing to do, since it does not require any software at all, and can be used with any OS. You can set up how thorough and what categories of filtering you want it to perform. Pretty amazing, for free. It can be used separately, or with dnsmasq, etc.

I can definitely relate to your point on how long it takes (in your spare time) to set things up.

jeff_k 03-22-2009 08:20 PM

This looks interesting, haven't tried it though:

rbees 03-22-2009 09:12 PM

Hey jeff k,

I don't use dns on my current firewall and I allready have bind9 setup on the new one. I strugled with that for a couple of weeks to get the kinks worked out of it. Not sure that I want to change up now. Besides, bind9 will do the same things.

Nice tip about the opendns site. I will be looking into that. At some point I want to setup a dynamic ip/dns for the web/mail-server that is my next porject. But I have to get the new firewall done first. The old one will become the web/mail-server.

There you have that.

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