No connectivity to an instance when using external network with network type VLAN

When using external network to Openstack Neutron with network type VLAN and creating a router there are no flows for this VLAN.
The workaround is to create a VLAN interface and add it to br-ex to have external connectivity to/from the VM.

How to reproduce
================
1. Create an external network with VLAN
2. Create an internal network
3. Create a router and add the internal and external network to the router
4. Launch an instance connected to the internal network, create a floating IP and associate the floating IP to the instance
5. Ping the floating IP from external network and verify it fails

Version
========
RHEL7.2
python-neutron-7.0.4-3.el7ost.noarch
openvswitch-2.4.0-2.el7_2.x86_64
opendaylight-1.0.0-2.el7ost.noarch