Yesterday I installed Ubuntu 9.10 (first time in my life) and conigured internet with pppoeconf. I entered username, password and pressed "yes" and "ok" in the other windows. Anything was ok, internet worked good. I rebooted couple of times, internet was ok.
Today I turned on the computer and there was no internet. plog outputted something like "CHAP authentication failed, unit [number]". I ran pppoeconf again, nothing changed, only the number became different. I thought I could be a provider's problem, but when I booted form LiveUSB and ran pppoeconf, internet was ok.
I changed nothing in the system, just installed a couple of packages, updates and the Russian language.
What can I do to solve the problem?