Comment 1 for bug 97451

I experienced the same issue.

I decided to investigate, and found that the IP address was in the right subnet, the DNS servers were correct, so I investigated the route and found this:

On system start my routing table looks like this:
64.230.197.93 * 255.255.255.255 UH 0 0 0 ppp0
192.168.0.0 * 255.255.255.0 U 0 0 0 eth0
link-local * 255.255.0.0 U 1000 0 0 eth0

there's no default route. This is what it looks like after poff && pon dsl-provider:
64.230.197.93 * 255.255.255.255 UH 0 0 0 ppp0
192.168.0.0 * 255.255.255.0 U 0 0 0 eth0
link-local * 255.255.0.0 U 1000 0 0 eth0
default * 0.0.0.0 U 0 0 0 ppp0

Trying to figure out how ubuntu starts it's ppp connection led me to /etc/ppp/pppoe_on_boot but I couldn't find a script that called it. Perhaps this is an issue with avahi or another package that modifies the kernel routing table. Either way, I wasn't able to find a cause for the missing default route.

Best,
Hugo