Patent ID: 7499999

Claim:
A method for blocking access to one or more protected devices on a computer network-by a client device having a physical device address, comprising the steps of: (a) receiving address resolution requests broadcast on the computer network by the client device seeking access to one of the protected devices, each of the one or more protected devices having a physical device address; (b) processing the address resolution requests to determine whether the client device is an unknown device; (c) if the client device is unknown as determined in step (b), placing the client device in a restricted status, and transmitting restricted address resolution replies to the protected on the computer network to block access to the protected devices by the client device and allow access to an authentication server; (d) if the client device is unknown as determined in step (b), monitoring the authentication server to determine if the client device is authorized or unauthorized by the authentication server; (e) if the client device is authorized as determined in step (d), removing the restricted status for the client device and allowing access to the protected devices; and (f) if the client device is unauthorized as determined in step (d), changing the restricted status to a blocked status and transmitting block address resolution replies at predetermined intervals on the computer network to block access to the protected devices by the client device.