Parece que você está procurando pelo packetfence ... ele é executado no Linux ...
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 guest 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.
Você precisa usar packetfence + nessus ( artigo da wikipedia do nessus ) para impor a política de antivírus