This is a complicated scenario and there are a lot of variables involved. It sounds like you're either directly connecting your computer to the DSL modem, or you have it setup as a DMZ host in your router. In either of those cases, to the DSL modem, the JumpBox is like a completely separate computer so you would have to enable access to it explicitly. The details of how to do that depend heavily on exactly how your network is configured.

I have set up the PunBB Jumpbox, registered it, and set up some of the forums. I am able to connect using my internal LAN since it gives me IP addresses either starting with 10..... or 172.... I access the internet through ADSL, but my ISP doesn't seem to restrict port 80.

I cannot, however see anything from outside my network on the internet, although I have tried VMware and Parallels with a variety of networking options. In each case, I can access the Jumpbox/Punbb interface internally, yet when I connect from the internet, I cannot.

I can, however, see my default Apache page when I access my computer's IP on port 80. Is my Apache Webserver causing some kind of conflict? Even when I turn off the Apache Webserver through the Personal Web Sharing tab (I'm on a Mac), it doesn't allow access through the web.

Do I need to change Jumpstart's port settings? If so, how can I do this?

Thanks!