<p>A method is implemented in a network element that functions as one of a plurality of controllers for one of a plurality of areas of a split architecture network. The controller provides a control plane for the area of the split architecture network where the controller is remote from a plurality of switches providing a data plane for the area of split architecture network. The controller facilitates optimized routing across the plurality of areas of the split architecture network by providing limited intra-area link cost data to other controllers of other areas of the split architecture network and to traditional routers of a network including the split architecture network. The limited intra-area link cost data provides costs of each possible shortest path traversal of the area of the controller without providing all internal link cost data.</p>
