Software Defined Networking
What is it all about?
What is SDN?
Software-defined networking (SDN) is an approach to computer networking that allows network administrators to manage network services through abstraction of higher-level functionality.
This is done by decoupling the system that makes decisions about where traffic is sent (the control plane) from the underlying systems that forward traffic to the selected destination (the data plane).
Imagine SDN as a very big chassis based switch, which all the Leaf / Spine switches in your network are its Line Cards.
A highly available controller plays the role of Management / Supervisor in SDN. It tells each switch how to forward packets.