Management is an essential process to ensure the proper operation of computer networks. There are a lot of proposals to manage software-defined networks (SDN) from their application plane. However, such proposals share some shortcomings related to low automation of network management tasks, long time needed to handle network situations, and the lack of flexibility and workability. In this paper, we introduce JANO to overcome these shortcomings and investigate the feasibility of using automated planning and network functions' virtualization to manage SDN from a vertical management plane. JANO uses hierarchical task networks' planning to generate automatically plans that automate management tasks and reduce the time required by administrators to face network situations. Also, JANO performs an instantiation of the management orchestrator of network functions virtualization to provide flexibility and workability in the generation and execution of plans targeted to addressing network situations. We evaluate JANO in a proof of concept. The evaluation results corroborated that JANO is a feasible solution to manage SDN, since the planning time slightly and linearly increased with the number of primitive tasks that form a plan, the time-consuming needed by administrators to addressing a network situation was short, and the additional traffic was low.