What is OpenFlow?
If we tried to explain what OpenFlow is, a possible definition would be: OpenFlow is a protocol for controlling and interacting with forwarding behaviors of switches. It allows us to dynamically control the behavior of the switches in our network. Many SDN (software defined network) and Open Source projects use OpenFlow or support it as a plugin, such as OpenStack Neutron and OpenDaylight.
But It’s hard to grasp what it is, what it solves and how it works only using this brief description. In order to truly understand what is OpenFlow, we need to start from the beginning, before SDN era.