Currently the controller has a very simple network setup user facing (waterfront/kube api) versus cluster data/control plane what we call the private interface (everything else).

Allow the administrator to split the cluster data/control plane between physical interfaces on the controller.
Allow those interfaces to include virtual interfaces as well (e.g. VLANs), potentially a controller could then only need one interface.
Traffic splitting should focus on the control plane (PXE boot, image delivery), Ceph data plane, and the interpod communication fabric.