Software-defined networks

Software-defined networking alters the model for traffic flow control in computer networks by centralizing the control logic while also separating it from the data paths in the network components. This enables simpler administration of traffic flows, facilitating control at a higher abstraction level. Software defined networking is well established in the market, which shows in that it is employed by several popular products for highly complex IT systems. Software-defined networking has a firm foothold in data centers, with a trend towards also being used for IT systems with lower complexity. The purpose of the study is to provide the reader with a base-line knowledge on software-defined networking and the building blocks used. This knowledge is intended to facilitate discussions on software-defined networking when developing and maintaining IT systems, primarily within the Swedish Armed Forces and other public organizations. The report introduces what software-defined networking is and which building blocks are used. The report also discusses how networks can be affected by software-defined networking and how it relates to the IT-system perspective. The report is based on scientific publication, which largely centers on open solutions of software-defined networks, as there is a lack of in-depth information about proprietary solutions. Even though many of the problems that software-defined networking handles could be solved with previously available techniques, software-defined networking has proven itself as a useful technique that can simplify network administration, while facilitating the use of other techniques such as service chaining and micro segmentation. In addition to the benefits from softwaredefined networking, there are also drawbacks such as new potential pitfalls and attack surfaces, such as the central controller becoming an attractive target for adversaries.