STUMPED - can connect via LAN but not via Internet

[evets dranem]

Chris Swain wrote:

>Dear VNC List,
>
> 
>
>I'm writing with a question I've seen several people post on VNC message
>boards but I've never seen resolved.
>
> 
>
>Here's the problem: I can successfully access my Desktop PC via VNC when I
>connect from within my LAN (e.g. connecting via an internal IP address -
>192.168.1.104 works).  However I cannot access my Desktop PC when I try to
>connect from outside the LAN (e.g. connecting via an external IP address
>-71.105.67.xxx returns a "Failed to connect to server" message).
>
> 
>
>Here are some details about my configuration:
>
>1.    my ISP, Verizon, does not block VNC traffic.  I've called their tech
>support multiple times to confirm this and run tests.
>
>2.    My modem/router is an ActionTec GT704-WG, version 3.  I've talked to
>their tech support multiple times as well to confirm that VNC should work
>and to run tests.
>
>3.    Port forwarding is working properly on the router.  This is confirmed
>when I connect via an internal IP address
>
>4.    Turning off the Windows firewall does not fix the problem
>
>5.    I am running Windows XP Media Center Edition Version 2002, Service
>Pack 2 on the Desktop PC
>
>6.    Desktop PC has a static internal IP address
>
>7.    Remote access is enabled on the router
>
>8.    NETSTAT -AN shows that VNC ports (5800 and 5900) are listening
>properly 
>
>9.    This problem disappeared a week ago meaning I could access via an
>external IP address for a few days but then the problem returned (!?).
>
>10.   Before installing the ActionTec modem router I had the same problem
>with a Westell 6100 modem and Belkin router.  Before the Westell 6100 I had
>an old Westell DSL modem that allowed VNC traffic fine.
>
> 
>
>Any thoughts you may have would be most appreciated.
>
> 
>
>Signed,
>
> 
>
> 
>
>Chris "Stumped and Shut Out" Swain
>
> 
>
>--------------------------------------------------------------------
>
> 
>
>Chris Swain
>
>Asst. Professor
>
>Co-Director, EA Game Innovation Lab
>
>Interactive Media Division
>
>USC School of Cinematic Arts
>
>http://interactive.usc.edu/research/games
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>  
>
you have an error in logic
 

<quote> 3.    Port forwarding is working properly on the router.  This is confirmed
when I connect via an internal IP address
</quote>

the port forwarding typically does not work from inside to inside

from outside you would point realvncviewer at publicip   for the default port of 5900

or you could setup a vncviewer pointing to publicip:57900
and have the router do when public port = 57900 forward to insideip port 5900
to frustrate the scanning idiots

on the router firewall you will  need to make a rule that says

if you see traffic going to port xxx forward it to insideip:yyy

for example if the firewall sees publicip:5900   forward it to insideip:5900

71.105.69.224:5900     -> 192.168.0.100:5900