PacketFence - network access control system - Linux
The PacketFence development team has published version 3.2.0 of its open source network access control (NAC) system. PacketFence allows organisations to increase control over their network by enforcing authentication and registration for newly connected devices. It also enables abnormal network activity detection and the isolation of troublesome devices.

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http://www.packetfence.org/download/releases.html