I'm trying to use Windows Server 2008's Routing and Remote Access Server to share an ADSL connection which uses PPPoE, but I'm having no luck.

I can setup the connection as a broadband Internet connection in Windows, and it works.

I can share it using Internet Connection sharing, and it works (but it's not what I need).

I have installed and enabled the Routing and Remote Access Service and configured it for NAT with a demand-dial interface; I create the aforementioned interface using PPPoE with the exact same parameters used on the Windows connection; I connected it, and it seems to work: I can also see it gets its public IP address and DNS assigned correctly.

But it just doesn't work.

The server has no Internet connectivity at all, and PINGing anything on the Internet results in a cryptic "general error".

Any help?