I've finally managed get myself set up with ADSL on Linux. I went with Demon, as they've got a decent reputation, and their web page states:
"Host software support for:
- Windows 98, 98SE, 2000, ME and XP
- Mac OS 8.6,9 and X
Great! However, after the package arrived, I couldn't help noticing a few obvious differences between the "host software support" for Windows vs Linux:
- The CD contains Windows drivers for the USB modem. There are no Linux drivers (and you have to mount it with rock-ridge extensions disabled to see anything at all, which wasn't obvious).
- There are detailed step-by-step instructions showing how to set it up on Windows. Linux isn't mentioned on the printed copy, and the CD version contains a single line, telling you to download drivers from the 'net (How? I don't have drivers for my modem!! Didn't anyone spot this little problem when they wrote the instructions?)
- When I phoned up for support and said I was installing on Linux, the response was "Ha! Good luck!". Not what you want to hear. I pointed out that Linux is one of their supported systems but apparently "We don't have any training for that."
The problem was that the CHAP authentication was failing (I'd downloaded some drivers from sourceforge via my mobile phone's irDA port - painfully slow, but it worked). The helpdesk chap was friendly, but didn't seem able to suggest anything.
I got fed up and bought myself an ADSL modem router. Exactly the same problem. But this time when I phoned up and said I had a router, they suddenly had a whole load of useful test addresses to try which quickly narrowed the problem down to BT's exchange. Grr. BT fixed it after a couple of days, and it's all been fine since, but I think describing Linux as supported is really stretching things!