First thing to check is this: Do you REALLY have connectivity to the required port on each PC? Obviously, you tried to set it up that way, but one problem that seems to be pretty common is issues with weird routers that don't do what you expect - so possibly you are rpevented from contacting those systems at all.
The way you test that is to either use a port scanner that returns the server response on each VNC port you want to connect to, or telnet to the port you need to reach. Here's a telnet example in case you aren't used to this. Suppose you have a VNC server running on a Win95 box with a private address (maybe 192.168.1.25); the VNC server is set to use Display 1 which means the port number it uses is 5900+1=5901. The router has a public IP of 10.10.10.1. You would telnet to 10.10.10.1 5901 to test this. If the VNC server is accessible, you will get back this response in your telnet client: "RFB 003.003" ------------------------------------------------------- IF THAT WORKS You have a problem with how the server is running - you will probably be getting a timeout in the VNCViewer or it may just hang indefinitely. ------------------------------------------------------- IF IT DOESN'T WORK Telnet may fail in one of 2 ways. If it immediately pops back with a refused connection, there is a node getting the traffic for the port, but it isn't running a VNC server. If it takes forever and times out, there's nothing listening on that IP/port combo. Some things to check if it fails (most likely, based on what you know). (1) Are the unreachable machines somehow set to use DHCP? If so, they are changing their local addresses meaning of course that the port forwarding is wrong within hours of when it is configured. A silly-sounding oversight, but I've done it myself. This sounds unlikely since you can track down the machines when you "chain" VNC connections. (2) check what the failing systems have in common. Are they all behind a particular type of router? Connected via the same ISP? ------------------------------------------------------ FOLLOWUP Here is some information you may want to post if you don't suddenly see something that clears it all up. (1) Router types (3) Any patterns you see and special things you did to share connectivity - in other words, do the sites have multiple public IPs? Did you set the systems to use different Display numbers? Are you using the VNC viewer application or the Java applet? What ranges of ports did you forward and how? It's a laundry list, but the "telnet" test gives you some solid information that lets you isolate the technical area in which the problem is occurring. Good luck, this one sounds like a fun one. On the bright side, it does sound like there is some overall pattern, so it may be easy to resolve the problem once the cause is found. My guess is that there is a problem with port forwarding at this point. You can get into each network remotely to at least 1 machine, and once you do that, you can further reach the externally unreachable systems. This points to port mappings not taking you inside to the correct system. ----- Original Message ----- From: "Klaas-Jan Doeven" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday/2002 February 01 06:05 Subject: one remote pc works, others NO GO!? : (i'll try it again, maybe a second posting) : Hello, : : I have a (weird) problem with VNC (windows version 3.3.3r9). : I installed it on several computer in a network somewhere else / remote. : I want to access the (remmote) VNC computers from remote through cable/ADSL. : The remote locations have routers, in these routers i configured NAT for the : specific ports, for the specific remote computers (local IP numbers, port : numbers 5900, 5901, etc). : At one location i have no problems at all, i can reach all the 'assigend' : computers in the network from remote. : But at one location i can only reach one computer (the server, running WinNT : 4.0) and NONE of the other computers who are also running the VNC service. : The other computers are running Win95 and Win98SE. : : At another location I can reach the server (again WinNT) and one from the : two computers running the VNC service, the other one is unreachabe (also : W9x). : At both locations locally, VNC works perfect, locally I can reach all the : VNC computers. So from remote i can reach the other computers THROUGH the : server, at least the computer which DOES work from remote. This is kind of a : 'long way' isn't it!! : Do you have any idea what is/can be the matter?! : : thanks : --------------------------------------------------------------------- : To unsubscribe, mail [EMAIL PROTECTED] with the line: : 'unsubscribe vnc-list' in the message BODY : See also: http://www.uk.research.att.com/vnc/intouch.html : --------------------------------------------------------------------- --------------------------------------------------------------------- To unsubscribe, mail [EMAIL PROTECTED] with the line: 'unsubscribe vnc-list' in the message BODY See also: http://www.uk.research.att.com/vnc/intouch.html ---------------------------------------------------------------------
