Although Software-Defined Networking can simplify network management, it also poses new testing and debugging challenges for operators. Debugging is often an interactive process that involves stepping through data- and control-plane events and performing actions in response. Sometimes, however, this interactive process can become highly repetitive; in such cases, we should be able to script the activity to reduce operator overhead and increase reusability. We introduce SIMON, a Scriptable Interactive Monitoring system for SDN. With SIMON, operators can probe their network behavior by executing scripts for debugging, monitoring, and more. SIMON is independent of the controller platform used, and does not require annotations or intimate knowledge of the controller software being run. Operators may compose debugging scripts both offline and interactively at SIMON’s debugging prompt. In the process, they can take advantage of the rich set of reactive functions SIMON provides as well as the full power of Scala. We present the design of SIMON and discuss its implementation and use.