A network may include a core region having routers and peripheral regions coupled to the core regions. Switches controlled by a controller may be interposed between the routers. The controller may maintain network topology information of the network. A path computation module may identify forwarding paths between the network routers based on the network topology information and other information such as network traffic history, current network traffic conditions, future network traffic forecasts, or other desired network information. The controller may control the switches to implement the identified forwarding paths. The controller may detect network topology changes and update forwarding paths based on the detected network topology changes. The controller may determine weights of path segments of the network topology. A routing module may provide the path segment weights to the routers using a network protocol.