[rdo-list] Adding a vlan to the external network in tripleo

I have a lab situation where there are 2 networks. One is in one DMZ and the other is a lab isolated network. I need access to both via the external port. I believe what I need to do is add another port to the bridge on a vlan to the lab network. I created a new external network in Director and assigned the vlan to it. However, I am not sure that will add it to the existing bridge. A bigger question around this is why does Openstack not support modifications after installation to the north/south network? East/west is easy but North/South has to have a lot of modifications made to static files (it seems) like plugin.ini and openvswitch.ini. Any help would be appreciated.