The extension manager for ML2 was introduced in Juno (more details can be found in the approvedspec). The features allows for extending ML2 resources without actually having to introduce cross cutting concerns to ML2. The mechanism has been applied for a number of use cases, and extensions that currently use this frameworks are available under ml2/extensions.
其他extension都是对core资源的扩展，不对ML2的资源进行扩展。
dns_integration.py Use converters and validators from neutron-lib 18 days ago port_security.py Use converters and validators from neutron-lib 18 days ago qos.py ML2: verify if required extension drivers are loaded
ML2的资源有哪些？
原文：http://www.cnblogs.com/allcloud/p/5490267.html