Yeah, having two path to the same network without using proper bonding seems a bit wrong, also having two IPv4 interfaces providing a default gateway may break the routing table quite badly.
Please attach: ip link show ip addr show ip route show ip route get 1.2.3.4 This should help understand what's going on. ** Changed in: ifupdown (Ubuntu) Status: Confirmed => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/788301 Title: Networking fails with two interfaces on the same network To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ifupdown/+bug/788301/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs