On Mon, Aug 06, 2007 at 12:03:02AM -0400, Boyd Campbell wrote: > Good evening all, > > I'm using VNC to connect to a specific server on a remote LAN from many > different clients at many different locations. However, using the same > machine on one network vs. another, I'm either able to get into the server > in question fine or I get a black screen with no visual. The mouse is moving > on the server and a hard connection is made, but the client only gets a > black screen. IE: Using a single laptop, I can get connected instantly from > one LAN with no issues, yet from another LAN, black screen. I'm also able to > connect from different machines on the LAN's that work. All machines in > question thus far have been XP Pro, SP2, RDP & User Switching off (neither > of which really matter anyways, since I am indeed able to connect using the > same machine(s) from one network but not another). Also, the server in > question is behind a VPN router with port forwarding to 5900 on (hence our > being able to connect to begin with). I've even gone to lengths of messing > with the MTU & RWIN settings and used the TCP/IP Optimizer off from > SpeedGuide.net...all to no avail. > > I've searched many lists and Google high and low for answers to this > issue. As I'm sure you well know, this issue has been an issue for many > years with VNC, but I haven't been able to find any definitive answers by > the VNC folks or others. Most of the answers I've found were merely > suggestions that appeared to be just shots in the dark (simply my perception > based on verbiage). In my humble opinion, if this is to be a viable product, > then this issue needs to be addressed once and for all, being put under the > VNC FAQ's since it is most certainly a FAQ on every list I've found, > regardless of the domain I've found the issue listed on. But I've found > everything from simple answers to uber-geek answers, none of which have > helped and none of which I've been able to find on the VNC site. > > I very humbly state, if RealVNC, Ltd. expects me, my company and my > clients to drop cash for the Enterprise versions of this software, then > someone needs to show me that the tool will work from anywhere around the > world with an internet connection if I go with it. I'm using the free one > now as a POC. But thus far, things have been problematic at best, and I've > not been able to find any viable solutions from the VNC technical community > at large. > > I would very much appreciate any help you all can lend.
You say that you have played with MTU, does that include playing with the server? Did you try to disable its Path MTU Discovery which is my bet at what is wrong here (since largish amounts of data is not getting from the server to the client). Or maybe I should wager that the server (or some firewall) blocks the relevant ICMP messages needed for Path MTU Discovery... See http://www.netheaven.com/pmtu.html for some background on my wild guess. Cheers, Peter _______________________________________________ VNC-List mailing list VNC-List@realvnc.com To remove yourself from the list visit: http://www.realvnc.com/mailman/listinfo/vnc-list
