1. For a network controller that manages at least a hardware switching element and a software switching element that both implement a same logical network, a method comprising: sending management data to the hardware switching element using a database protocol as a single communication channel to add the hardware switching element to a set of managed forwarding elements that implement the logical network; when a forwarding state of the software switching element changes, sending the forwarding state of the software switching element to a database table of the hardware switching element using the database protocol; and when a forwarding state of the hardware switching element changes, receiving updated forwarding state from the hardware switching element, wherein the hardware switching element uses the management data and the state data to define forwarding table entries that implement the logical network, wherein the database protocol is the only communication channel through which the hardware switching element receives data from the network controller for configuring the forwarding table entries.