authentication - login credentials Cisco NAC Appliance L2 switch or L3 authentication Pre-installed security agent Web-based security agent Network packet signatures or anomalies External network vulnerability scanner External database of known systems Agent-less posture assessment Most NAC vendors require the 802.1x supplicant (client or agent) to be installed. Some, including Hexis' NetBeat NAC, Trustwave, and Enterasys offer an agent-less posture checking. This is designed to handle the "Bring Your Own Device" or "BYOD" scenario to: Detect and fingerprint all network attached devices, whether wired or wireless Determine if these devices have common vulnerabilities and exposures (aka "CVEs") Quarantine rogue devices as well as those infected with new malware The agent-less approach works heterogeneously across almost all network environments and with all network device types. See also Access control Network Access Protection Cisco NAC Appliance Network Access Control PacketFence References External links Network Admission Control - Cisco Systems Agent-less Network Admission Control - NetClarity, Inc. FastNAC Next-generation NAC Computer network security