This paper presents a case for applying the principles of Software-Defined Networking (SDN) to middleboxes and end hosts. The challenges of configuring networking on network hosts resemble those addressed by SDN – numerous multi-vendor components, each with its own syntax and idiosyncratic corner cases, must be orchestrated smoothly. We have developed a prototype called NativeClick, a novel use of the Click Modular Router language, to orchestrate Linux networking tools. NativeClick demonstrates that, while existing SDN efforts have produced insufficient Abstractions to cover a wide range of networking behavior, SDN-like abstractions can make host configurations modular.