UltraVNC SC + vncviewer /listen through openvpn not working

[ignasigarcia]

Hi there!

Here at my company we use the vncviewer /listen 5500 along with the UltraVNC SC located at our customer's systems to do some remote maintenance work. We have a DNAT entry in our firewall (shorewall) pointing to our techsupport computer, so when the customer needs assistance, it just has to execute the UltraVNC SC program. It works great!

However, I'm trying to setup the same thing but on a techsupport laptop that connects through an OpenVPN tunnel to our company. So, instead of DNATing from the internet to the desktop computer in my LAN, I setup a DNAT entry to the computer connecting through the tunnel. If I telnet mydomain.com 5500 from the internet I get a response from the laptop on the OpenVPN tunnel, so DNAT works. However, when I start the UltraVNC SC I get a Bad Protocol Error. I'm not using any encryption nor any plugin, just plain UltraVNC connection.

Does anybody know how I can make this work???

TIA

Ignasi