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Hi Bob and others planning on supporting ML2 -

While reviewing the ML2 design looking at how the Cisco sub-plugins could use (be rewritten) the mechanism driver I've come up with a few questions.

1.) Although not necessary, I'm guessing that the Ml2Plugin would be used as the core_plugin. Is this true?
      If used as a core_plugin then the actions taken by received events (create_network, create_port, etc.) are written to support the OVS or LinuxBridge
      vSwitches. I'm guessing this works for most deployments but will be an issue when using the Cisco N1K plugin.  For Cisco, N1K replaces the OVS
     plugin.  We may have to create/rewrite/inject a Cisco core_plugin when using the Cisco N1K under the ML2 design. Which honestly is something
     we wouldn't want to do.
     Will any other existing plugins have this issue?

2.) Taking the case were an OVS vSwitch is being used with an external device (mechanism_driver), we'll need to roll back the action taken on an OVS
      event if there is an error on the action taken for the external device.
      i.e. the create_port() events occurs, Ml2Plugin create_port() called and is successful, mechanism_driver(s) create_port(s) are called. If an error 
     occurs here then the Ml2Plugin delete_port() should be called.
     I realize this code hasn't been written yet but wanted to see if others agreed with this design. 

Thanks,
Rich