The Modular Layer 2 (ML2) plugin is a framework that allows OpenStack Networking to simultaneously utilize a variety of layer 2 networking technologies that are found in data centers. The ML2 plugin works with existing Open vSwitch and LinuxBridge agents and is intended to replace the monolithic plugins associated with those agents. The ML2 framework greatly simplifies adding support for new L2 networking technologies, as less effort is required to add functionality compared to creating a new monolithic core plugin.

In Havana, ML2 can be configured to support the following network types:

The ML2 plugin has its own configuration file that must be used in conjunction with the Open vSwitch or LinuxBridge configuration file. The configuration of ML2 is documented in the upcoming sections.