Book excerpt: This book is written to explain SDN for educational purposes. In addition to the general discussions of SDN, it focuses on one of the most promising protocols of SDN: OpenFlow. This book also touches on other SDN implementation, VxLAN. The book gives an overview of the SDN and then goes in depth of Open flow technology and VxLAN. In openflow it has following explained: - Why Openflow - Openflow Events - Openflow components - Openflow Case study with wireshark captures - All kind of Openflow packets, with details of each field. In VxLAN it has following explained: - Why VxLan - VxLAN events - VxLAN case study - All VxLAN packets, with details of each field. A good read for Developers, testers, network admins & anyone who wants to know SDN and wants to start from scratch and end up knowing end to end of Openflow & VxLAN.