vnc issues.
 

Has anyone trie setting up vnc though a dlink firewall/router?
I'm trying to use UltraVNC (but tightVNC not working either) and cannot connect to it from outside of the firewall.
Within the firewall in the internal network, computers can connect fine, but from without, it just doesn't go.
IT's currently set to port forward ports 5900 and 5800 to the internal machine running the vncserver.
One thing that is odd is when I connect internally, then try to do a connection coming from an external site, it seems to work.
any suggestions?

Check your XP svc pack 2 firewall on the pc to make sure it's permitting for traffic OUTSIDE your internal subnet.
Check your DLINK config to see if that traffic is permitted, it might not be, even with the NAT rules set up. You want pass thru to be active for that internal IP (host), permitted to the source IP (client) of your chioce.

also check within vnc to make sure you allow traffic outside your local lan. On RealVNC, it is on the connections tab in properties.

You will be unable to VNC into anything on your network if you're running stock SP2. It has the firewall enabled. You can always test this by trying to ping something as well, because the firewall also blocks incoming ICMP echoes, possibly outgoing too.

Enable port forwarding on your router if you're trying to come from the outside into the network. NATting is suggested.

port 5901 should also be forwarded.

5900 = display "0", 5901 = display "1", 5902 = display "2", etc. so 5900 should be sufficient for a root VNC display. I have to agree with the other posts; you're probably experiencing an XP firewall problem.