OFTEN testing OpenFlow networks

Software-defined networking and OpenFlow in particular enable independent development of network devices and software that controls them. Such separation of concerns eases the introduction of new network functionality, however, it leads to distributed responsibility for bugs. Despite the common interface, separate development entails the need to test an integrated network before deployment. In this work-in-progress paper, we identify the challenges of creating an environment that simplifies and systematically conducts such tests. We discuss optimizations required for efficient and reliable OpenFlow switch black-box testing and present a possible approach to address other challenges. In our preliminary prototype, we combine systematic state-space exploration techniques with real switches execution to explore an integrated network behavior. Our initial results show that such methods help detect previously unrevealed inconsistencies in the network.