PacketFence Free and Open Source NAC

https://packetfence.org/

PacketFence is a fully supported, trusted, Free and Open Source network access control (NAC) solution. Boasting an impressive feature set including a captive-portal for registration and remediation, centralized wired and wireless management, powerful BYOD management options, 802.1X support, layer-2 isolation of problematic devices; PacketFence can be used to effectively secure networks small to very large heterogeneous networks.

Released under the GPL, PacketFence is built using trusted open source components that allows it to offer an impressive amount of features.