How to setup PPPoE connection over wired DSL connection (Ethernet)?
I'm using Ubuntu 12 dual-booting with windows. It runs OK. on windows
If you have a decent router, the PPPoE connection is (or should be) handled in the router and is stored in it, unaffected by power down resets. The connection to your computer becomes a VPN to the router (LAN). Very few routers (only very old ones) need the PPPoE to be reset for every computer or operating system. If they do, you have very little firewall protection between you and the web, in which case I'd recommend a new one, SMC, Netgear etc. .... You can boot in windows and check the connection settings there, make a note of them including any passwords, then boot back into Ubuntu and make sure the connection is the same. Ubuntu nearly always finds the correct settings for a LAN entirely on its own, unlike some others!