The Extreme L3 Service plugin 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 L3 networking constructs.
The L3 Service plugin can create a distributed or centralized VRF instance on the IP fabric which corresponds to the Neutron router settings.
For distributed routers, VRF instances are created on corresponding leaf devices. For centralized routers, VRFs are created on border leaf devices only. For more details, see Distributed and Centralized Routing.