Network Access Control (NAC) examines the current state of network device before it is allowed to connect to the network. Any device that does not meet a specified set of criteria is only allowed to connect to a “quarantine” network after the security deficiencies are corrected. NAC Prevents computers with sub-optimal security from potentially infecting other computers through the network. This technology uses, protocols such as Dynamic Host Configuration Protocol (DHCP) server and Address Resolution Protocol (ARP).