VNC-List digest, Vol 1 #780 - 33 msgs re Server uses wrong (internal LAN) IP support "at"
Mon Jan 26 14:39:00 2004

You need to open the firewall of the router to allow port 580x and 590x
(say 5801 and 5901) to the internal IP of the machine you want to connect
to, then set up the server user properties to a fixed display number. (say
1). You then connect the viewer to the public ip of the router with :1

Swcond server on the internal lan would be set up as display 2 and addressed
as :2