PacketFence is a network access control (NAC) system. It is actively maintained and has been deployed in numerous large-scale institutions. It can be used to effectively secure networks, from small to very large heterogeneous networks. PacketFence provides NAC-oriented features such as registration of new network devices, detection of abnormal network activities including from remote snort sensors, isolation of problematic devices, remediation through a captive portal, and registration-based and scheduled vulnerability scans.