Comment 9 for bug 1531895

It seems that approach described in bug's description is correct. Currently, l23network generates following configuration for physical ports:
root@node-3:~# cat ifcfg-eth0
auto eth0
iface eth0 inet manual

but, it should look like(works for me):
root@node-3:~# cat /etc/network/interfaces.d/ifcfg-eth0
allow-br-fw-admin eth0
iface eth0 inet manual
ovs_type OVSPort
ovs_bridge br-fw-admin