What type of SDN employs both traditional and software-defined networking protocols?

Hybrid SDN is the type of software-defined networking that utilizes both traditional networking protocols and software-defined networking protocols. This approach allows organizations to integrate their existing network infrastructure with new, transformative SDN technology, thereby enabling a smooth transition to more flexible and programmable networking environments.

By employing both sets of protocols, Hybrid SDN provides the ability to maintain legacy systems while taking advantage of the innovative capabilities that SDN offers, such as improved resource management, scalability, and automation. This flexibility is crucial for organizations that want to evolve their network capabilities without abandoning their current investments in hardware and traditional network management techniques.

The other options do not encapsulate this dual-protocol nature. Overlay SDN focuses more on creating virtual networks on top of existing physical networks, and while Open SDN emphasizes a fully software-defined framework where traditional protocols may not be used, Static SDN refers to configurations that do not adapt flexibly to changing network conditions, further distinguishing it from the adaptive features of Hybrid SDN.