Looking at this, it looks like an apparmor issue. udev isn't related at all with building up network connections.
[ 1236.868192] type=1400 audit(1378323693.244:15): apparmor="DENIED" operation="capable" parent=1387 profile="/sbin/dhclient" pid=1474 comm="dhclient" pid=1474 comm="dhclient" capability=12 capname="net_admin" ** Changed in: udev (Ubuntu) Status: New => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1220918 Title: networking does not come up in cloud image on hyper-v To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1220918/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs