Lion Server VPN, Can Connect Locally, Not Remotely
I have both Lion and Lion Server installed on my Core 2 Duo iMac, mainly because I want the VPN feature of Server.
I configured everything correctly for the VPN, and can connect to it with no problems from my iPhone and iPad when I am within my own LAN (the server and the iPhone/iPad are on the same IP range and subnet).
I also used the automatic config within the Server app to configure my AirPort Extreme N Base Station. Looking at the Port Mapping section of my ABS from within AirPort Utility, I do in fact see that VPN Service (L2TP) is configured with the following UDP ports: 500, 1701 and 4500. Those ports ARE pointing to the iMac that is running the VPN server. Firewall on that iMac is turned OFF.
However, I am unable to connect my iPhone to the VPN Server using my Public IP address. I have tried it from within my network (out of network to internet the back), from my Verizon MiFi or from my iPhone's 3G connection (well, in my area it is still Edge). The iPhone simply sits on "Connecting" for a few seconds, then an alert comes up stating "The L2TP-VPN server did not respond. Try reconnecting. If the problem..." yadada.
I AM, however, able to get Web Sharing to work via my Public IP address, as well as VNC.
I also cannot connect to the VPN via the Public IP with other devices like my iBook, PowerBook G4, Windows 7 PC, or iMac G5. They ALL CAN connect via the local network 10.1.x.x IP address.
Am I missing something here? I did all of the automatic configurations, and all of the ports appear to be properly open.
iMac, Mac OS X (10.7)