port forwarding - Why can't I connect to my VNC server from outside my network?

I have a computer running TightVNC server. It is on my home network. The computer it is installed on has a locally static ip address 192.168.1.100. I am able to connect to this vnc server from my home network fine, but unable to connect from outside my network (using the IP address that I see at www.whatismyip.com).

I have forwarded port 5900 (and 5800) to ip address 192.168.1.100. But if I use canyouseeme.org I am unable to see that port.

I am running Windows 7.

Any suggestions?

Answer

I would double check that you have forwarded the port as that is all you should need to do.

If there is a problem, try changing the default port in case your ISP is blocking it.

Lastly, you may want to double check that you have forwarded the correct protocol, I can't remember if it is TCP or UDP that is needed, but if you have one - try the other (or both!)