The Modular Layer 2 (ml2) plugin is a framework allowing OpenStack networking to simultaneously utilize the variety of layer 2 networking technologies found in complex real-world data centers.
External networks are managed using ml2 Mechanism Driver. The mechanism driver is responsible for taking the information established by the type driver and ensuring that it is properly applied, given the specific networking mechanisms that are enabled.
The following figure shows an overview of the ML2 mechanism driver within Neutron.
Extreme ML2 Mechanism driver within the Neutron component of OpenStack proxies the Neutron API calls for network management toward the OpenStack Service running in EFA.
The OpenStack Service in EFA translates the neutron network management calls to appropriate tenant API calls and provision the fabric with appropriate L2 networking constructs.