Online Help

Port forwarding NAT/router/firewall for any VNC flavor

UDP port is not used, if possible don't open unused port by VNC

If your ISP provide you a dynamic IP to you, you need to subscribe to a dynamicDNS service provider supported from your NAT broadband router and put your hostname freshly created and configure it to forward external port to your internal ip address port of your NAT/ broadband router
or
If your ISP provide you a static IP to you, you need to forward external port to your internal LAN port IP address configure it to your NAT/router.

myhost.domain.com:5900 --> redirected internally to 192.168.1.100:5900
myhost.domain.com:5901 --> redirected internally to 192.168.1.101:5900
myhost.domain.com:5902 --> redirected internally to 192.168.1.102:5900
myhost.domain.com:5903 --> redirected internally to 192.168.1.103:5900
myhost.domain.com:5904 --> redirected internally to 192.168.1.104:5900

Incoming from WAN to LAN
port 5500 TCP protocol --> ip/hostname --> vncviewer listening
port 5800 TCP protocol --> ip/hostname --> winvnc http VNC server http
port 5900 TCP protocol --> ip/hostname --> winvnc rfb VNC server
port 5901 TCP protocol --> ip/hostname --> ultravnc repeater
port 0443 TCP protocol --> ip/hostname --> https ssl (and repeater_ssl)

Outgoing from LAN to WAN
(necessary only for enabled firewall like XP SP2 Windows Firewall or any strong software/hardware firewall)
port 0443 TCP protocol --> ip/hostname --> https ssl or repeater_ssl (SingleClick III aka SCIII)
port 5500 TCP protocol --> ip/hostname --> winvnc reverse connection (SingleClick)
port 5800 TCP protocol --> ip/hostname --> web browser act as vncviewer
port 5900 TCP protocol --> ip/hostname --> vncviewer

http://www.portforward.com/routers.htm
has a long list of different routers and easy step by step on port forwarding for almost any broadband router including (ADSL/CATV)

Just select your broadband router brand, then the router model, then select VNC from the list of programs to forward. It will show, pictures and all, how to forward a port for VNC.

Hint from butchthedog
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FQDN= Fully Qualified Domain Name
A fully qualified domain name consists of a host and domain name, including top-level domain.
For example, www.uvnc.com is a fully qualified domain name.
www is the host,
uvnc is the second-level domain,
.com is the top level domain.

For reach your vnc server from vncviewer:

for reach your vnc server from web browser:

port 80 is standard http port and not usable if you have web server
but 5800 is not a standard port for http so you need follow step below:

don't forget to put http:// in header

• external usage (outside of your office, home from your web browser)
  reach vnc server over Internet with FQDN address (with right access )
  or your own rent a static public IP address ((you know because is on your contract)
  
  example:
  http://myhost.dynamicdns.org:5800
  http://public_ip:5800
  http://123.123.123.123:5800
  
  or
  
  
• internal usage (inside your home/office LAN from your web browser
  example:
  http://hostname:5800
  http://private_ip:5800
  http://192.168.1.101:5800