VNC in listening mode, connection fails with "read: Connection reset by peer (10054)

[Kevan Rehm]

Philip,

Thanks for your reply.  I've managed to work around the problem, but thought 
I should give an update just in case anyone else runs into the same thing.

First, I do understand that I shouldn't have to port-forward 5900 and 5800; 
I had simply reached the point where I was willing to try anything.  :-)  I 
have since disabled them again.  Also, my DDNS address is working correctly, 
the IP address I get when I ping the hostname matches the address I get when 
going to WhatIsMyIP.com.   The Belkin also seems capable of updating the 
DDNS correctly, the Belkin documentation actually tells you to register your 
name at DynDns so that it can be automatically updated, so I'm willing to 
believe that they actually tried it before shipping.  :-)

I have come to believe as you do that this is some quirk having to do with 
having one machine on an internal LAN talking to another on the same 
internal LAN but using an external address.  After I read your email, a 
light bulb came on, and I used one of the internal LAN machines to 
SSH-tunnel to my office across town, effectively putting that machine 
outside the internal LAN (its IP address was now that of an office machine). 
In this configuration I was able to connect from that tunneling machine to 
my VNC-listening machine using the external DDNS name.

The only reason I was going through all this is because I am setting up a 
computer for my in-laws and testing it before taking it over to their house. 
I wanted to make sure that they could connect back to my machine so that I 
could help them with any problems.  After my tunneling experiment, I now 
know that it will work correctly when I take the computer to their house, 
once it is off my internal LAN.

Again, I appreciate your help.  It's still an interesting problem as to why 
this doesn't work when both machines are on the internal LAN and an external 
address is used, but since it's only a temporary situation, I'm willing to 
give up trying to figure it out.  :-)

Regards, Kevan