US Patent 8966029 Network control system for configuring middleboxes

Some embodiments provide a method for configuring a logical middlebox in a hosting system that includes a set of nodes. The logical middlebox is part of a logical network that includes a set of logical forwarding elements that connect a set of end machines. The method receives a set of configuration data for the logical middlebox. The method uses a stored set of tables describing physical locations of the end machines to identify a set of nodes at which to implement the logical middlebox. The method provides the logical middlebox configuration for distribution to the identified nodes.