The answer to question 01: DoS Attacks The answer to question 02: A switch that supports 802.1X port-based access control can activate a port but only allow Extensible Authentication Protocol over LAN (EAPoL) traffic to pass through it. Before full network access is provided, the client device and/or user must be authenticated. The answer to question 03: A local agent operating on the host is used by some NAC solutions to perform host health checks. A dissolvable agent runs in the memory and CPU of the host but isn't installed on the local disk.