VNC-List digest, Vol 1 #1553 - 12 msgs

"Dr.Alexander Röhlich" alex "at"
Wed Nov 2 07:39:01 2005

Where's the problem??
1. Router port forwarding works by using the set of rules. as soon as 
one rule applies, all other rules are discarded. so all you are doing is 
sending all your traffic to pc The second rule is NEVER 
going to be used.
2. NEVER leave your ports open !!! NO program needs an open port except: 
programs which want to come in to your computer, i.e. VIRUSES, MALWARE 
and other cr*p. Oh, and of course VNC. That's one of the reasons 
antivirusprograms sometimes block it. All other programs which go out, 
i.e. internet explorer, netscape, etc.., will automatically receive all 
services which they have sent out for, so you do NOT need to open ports 
for them.
3. If you want to use two computers with vnc, you will need to use 
different ports, at least from the outside. If your router allows port 
change, then forward port 5900 to, and port 5901 to No need to change configuration of computers then. To 
access: externalIPaddress:5900 for computer and 
externalIPaddress:5901 for computer
4. Router: You will need to create a service called (for example) 
VNC5900 and asign port 5900, do the same for VNC5901, i.e. asign port 
5901. Then you can  use the diagramm below to allow inbound services. I 
can not see whether you can actually asign a different port on the way 
in, so you might have to change the port VNC is listening to on to 5901 as well.

good luck.

>Message: 2
>Date: Tue, 1 Nov 2005 15:37:34 -0500 (EST)
>Subject: Re: What on Earth is Session Zero?
>From: "William Hooper" <whooper "at">
>To: vnc-list "at"
>Stephen wrote:
>>The router is configured to allow everything inbound to both as
>>Inbound Services
>>#  Enable  Service Name  Action  LAN Server IP address  WAN Users  Log
>>1   Yes Any(ALL)  ALLOW always  Any  Always
>>2   Yes Any(ALL)  ALLOW always  Any  Always
>>Default  Yes  Any  BLOCK always  Any  Any  Never
>What brand and model of router?
>Without more information, I would say your problem is that you are trying
>to forward all the ports to two machines, so your router is ignoring the
>second machine.
>I see you have logging enabled, so why not look at the router log and see
>what it says about your attempts to connect to the WinXP machine.