1. For a network controller that manages switching elements to implement logical datapath sets (LDPSs), a method comprising: configuring a first plurality of managed edge (ME) switching elements to forward packets for a first LDPS; configuring a second plurality of ME switching elements to forward packets for a second LDPS; configuring a first managed non-edge (MNE) switching element to forward a first packet between first and second ME switching elements in the first plurality of ME switching elements, when the first ME switching element cannot forward the first packet to the second ME switching element; and configuring a second MNE switching element to forward a second packet between third and fourth ME switching elements in the second plurality of ME switching elements, when the third ME switching element cannot forward the second packet to the fourth ME switching element, wherein configuring the ME and MNE switching elements comprises providing data for specifying flows in the ME and MNE switching elements to forward packets, wherein the specified flows define forwarding behavior of the first and second pluralities of ME switching elements that effectuates the first LDPS and the second LDPS, respectively.