An Software Defined Networking (SDN) router translates routing information from a standard routing control plane into forwarding decisions on an SDN-enabled device. This thesis presents the design of RheaFlow an SDN router that uses Internet Protocol (IP) routing control logic to modify forwarding behaviour on OpenFlow switches. RheaFlow is implemented as a set of network applications on the Ryu OpenFlow controller platform. It utilises the Ryu Application Programming Interface (API) to build a modular SDN router architecture that is easily extendable and simple to configure. RheaFlow adopts and improves the IP routing via OpenFlow based on the approach of RouteFlow, an existing SDN router. The RheaFlow design cen- tralises the routing control plane which is distributed in RouteFlow. It also removes RFProtocol, an internal control protocol used by RouteFlow.