I've been bitten by this bug, too, until I figured out what's wrong. I wanted to report it, but found this bug report instead, so I'm adding a comment.
As Elie Morisse explained already, the boot order has changed from Breezy to Dapper, now /etc/init.d/pppd-dns is linked to /etc/rcS.d /S55pppd-dns instead of /etc/rcS.d/S38pppd-dns as it used to be. Since it runs after networking is brought up (which, thanks to pppoeconf, already has activated the ppp connection), it discards the (until then valid) /etc/resolv.conf. We end up with an established ppp connection but without DNS servers to resolve domain names. The work-around would be to disconnect (sudo poff) and reconnect (pon), but a real fix is changing the boot order back to how it was set up under Breezy. I'm pretty sure a lot of people don't even notice that the ppp connection is up and that the DNS is being mangled, instead they will assume that there's no Internet connection after boot-up, despite having configured it that way. In addition to that, bringing up a working Internet connection on boot up is vital for headless servers, so I consider this bug of high importance. Thanks, -- Stefan D. Schwarz -- pppd makes a resolv.conf backup, then pppd-dns immediately restores it https://launchpad.net/bugs/49151 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
