We present our preliminary work in using argumentation logics to reason about security administration tasks. Decisionsabout network security are increasingly complex, involvingtradeoffs between keeping systems secure, maintaining system operation, escalating costs, and compromising functionality. In this paper we suggest the use of argumentation to provide automated support for security decisions. Argumentation is a formal approach to decision making that has proved to be effective in a number of domains. In contrast to traditional first order logic, argumentation logic provides the basis for presenting arguments to a user for or against a position, along with well-founded methods for assessing the outcome of interactions among the arguments. We demonstrate the use of argumentation in a reconfiguration problem, to diagnose the root cause of cyber-attack, and to set policies.