Software Defined Networks: A Comprehensive Approach, Second Edition provides in-depth coverage of the technologies collectively known as Software Defined Networking (SDN). The book shows how to explain to business decision-makers the benefits and risks in shifting parts of a network to the SDN model, when to integrate SDN technologies in a network, and how to develop or acquire SDN applications. The book emphasizes the parts of the technology that encourages opening up of the network, providing treatment for alternative approaches to SDN that expand the definition of SDN as networking vendors adopt traits of SDN to their existing solutions. The book also has an excellent survey of the technologies involved in SDN. This helps individual networking and engineering professionals transition to careers as developers of DevOps roles in SDN. The structure of the book has been modified to support professional or university instruction in the area of SDN. Since the first edition has been published, the SDN market has matured, and it is being gradually integrated and morphed into something more compatible with mainstream networking vendors. Software Defined Networks: A Comprehensive Approach, Second Edition reflects these changes. New to This Edition. . . Coverage of the OpenDaylight controller and its support for multiple southbound protocols. . . . ONOS from [...], targeted to Service Providers and supporting HA with its first release. . . . Inclusion of NETCONF in discussions on controllers and devices. . . . Expanded coverage of NFV. . . Updated coverage of the latest approved version (1.5.1) of the OpenFlow specification. . . Structure of book changed to support professional and student instruction, with ancillary materials created to support SDN instructors.