What is the ML2 plug-in? Explain its architecture

ML2 (Modular Layer 2) is a framework that allows OpenStack to simultaneously utilize a variety of layer-2 networking technologies. It replaces the monolithic plugins for individual network types and provides a more flexible and extensible architecture. ML2 uses a combination of Type drivers (for network types like VLAN, VXLAN, etc.) and Mechanism drivers (for connecting to different network mechanisms like Open vSwitch, Linux Bridge, etc.).