Patent ID: 7448076

Claim:
An apparatus for controlling access to one or more protected devices each having a physical device address on a computer network by a client device having a physical device address, comprising: a central processing unit; a network interface configured to receive address resolution requests broadcast on the network by the client device seeking access to one of the protected devices and to transmit address resolution replies generated by the apparatus on the computer network; and a security module running on the central processing unit and configured to: (a) process the address resolution requests from the client device to determine whether the client device is unknown; (b) transmit address resolution replies on the computer network to block access to the protected devices and allow access to an authentication server, if the client device is unknown; (c) monitor the authentication server to determine if the client device is authorized or unauthorized by the authentication server, if the client device is unknown; (d) allow access to the protected devices, if the client device is authorized; and (e) transmit blocking address resolution replies on the computer network to block access to the protected devices, if the client device is unauthorized; wherein the apparatus is connected as a peer device on the computer network.