Comment 7 for bug 1773377

> this will allow us to bind this "dns-provider" endpoint to a space on the designate-bind side (no need for extra-bindings)

> * document a requirement that network engineers should route traffic from provider network subnets to a network space used in "dns-provider" endpoint binding;

This suggests that the relation between designate-bind and neutron-{gateway,openvswitch} has to be on a routable network, and non-routable (isolated) network cannot be used. Also, the host OS of neutron-gateway/openvswitch will be exposed as routable from provider networks which is unnecessary.

I may be missing something, but extra-binding sounds straightforward since vlan provider networks are managed outside of Juju model anyway.