If you have an DIR-100, you may encounter a problem with setting remote management.
The manual says: just enable the remote management, select the port and save the settings...
Do not believe! Until you reboot the router, you will unable to contact to your router from internet.
If the DLINK guys read this post: you'd better update the manual and online help of this router.
Once the router rebooted, you can manage it over Web.
Every boot does good!