Comment 19 for bug 1084028

Ubuntu 14.04.5 (Open vSwitch) 2.0.2 (installed with apt install openvswitch-switch)

Following configuration works for me, also after reboot:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
allow-br-ex eth0
iface eth0 inet manual
ovs_type OVSPort
ovs_bridge br-ex

# The OVS bridge interface
auto br-ex
allow-ovs br-ex
iface br-ex inet static
ovs_type OVSBridge
ovs_ports eth0