Comment 1 for bug 1385709

After wasting a whole day on this, I think I found the culprit. I had to delete a whole bunch of files named 'sendmail' which were scattered around /etc (/etc/ppp/ip-up.d/sendmail /etc/ppp/ip-down.d/sendmail /etc/network/if-post-down.d/sendmail /etc/network/if-up.d/sendmail /etc/network/if-down.d/sendmail /etc/dhcp3/dhclient-exit-hooks.d/sendmail /etc/resolvconf/update-libc.d/sendmail, and there are a few more that should probably also be deleted). Note that I do not have the sendmail package installed at all!

I do not know, however, why the upgrade to 14.10 triggered this failure. Maybe it removed something related to sendmail, or started doing something with these files that were previously ignored... dunno. In any case, it's a pretty serious upgrade bug, since it prevents the network from connecting, and is quite non-trivial to trace back to its origin (there were lots of other errors/warnings in syslog that seemed related but weren't, and nothing there about these sendmail files or a hint as to the cause of failure).

The indirect reason this happens on wired connections is probably that there is a correlation between hosts which at some point had sendmail installed and those that are on a wired connection :-)

Please fix this issue quickly before others upgrade and lose their connectivity... (already encountered someone else with the same symptoms).