I'm seeing this as Thomas was so kind to mark it for Ubuntu after all the time. To finally answer your closing question, no this is neither a known bug nor reported anywhere else to my knowledge so far. Due to that I can't point to any "here it was fixed" change of later.
I have to beg your pardon after so much time and ask you if this still happens to whatever setup you have today. And if possible at least use Ubuntu Bionic for the much newer stack of virtualization software. For debugging I think you did what you'd expect. You could start switching device types from virtio to one of the emulated types just to check if it is related. Further pretty often in "manual" setups there are minor flaws (had some myself) that are already covered by quirks in libvirt. So the next step would to push your setup into a libvirt based guest and if it is working then comparing how it had started your guest. ** Changed in: qemu (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1463909 Title: virtio: networking not working when guest's eth0 is not in promiscuous mode To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1463909/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs