1.The resubmit action also enables a form of programming based on multiway branching based on the value of one or more fields
2.OpenvSwitch 2.6.90 without patch port for ovn's router, The clone action make packet re-entry openflow pipeline.
clone([action][,action...])
Executes each nested action, saving much of the packet
and pipeline state beforehand and then restoring it
afterward. The state that is saved and restored includes
all flow data and metadata (including, for example,
ct_state), the stack accessed by push and pop actions,
and the OpenFlow action set.
This action was added in Open vSwitch 2.6.90
3.OpenVSwitch的Datapath分为多种类型： Userspace datapath，Linux kernel datapath，OVS Tree datapath，Feather需要特定的datapath支持
