DHCP support for secure automatic detection of host status

Dynamic host configuration protocol (DHCP) is a dynamic IP address assignment scheme for assigning IP addresses to those non-IP-preconfigured clients. Applied with network address translation (NAT) scheme, a client with auto-configured private IP address on a private network can access to the public networks. This paper proposes an automatic notification scheme based on DHCP that allows the DHCP server to notify a banned server whose network interface is originally configured with a public IP address, and assign a new private IP address to this banned server to resume its network connection to the public networks.