Patent ID: 8312533

Claim:
A computer system configured to operate in accordance with a plurality of different security classifications, the computer system comprising: a computer comprising at least one processor; a virtual local area network switching device comprising a plurality of ports and in communication with the computer via at least one of the ports; and a plurality of peripheral hardware units in communication with the virtual local area network switching device via respective ports thereof, wherein the plurality of peripheral hardware units comprise at least one peripheral unit configured to have a first security classification and at least one peripheral unit configured to have a second security classification that is less secure than the first security classification, wherein the virtual local area network switching device comprises a memory configured to store information associating a plurality of the ports with the security classification of the respective peripheral unit in communication therewith, wherein the virtual local area network switching device is configured to receive a frame from a source device that bears an address of a destination device, wherein the source and destination devices comprise respective ones of the computer and the peripheral hardware units, and wherein the virtual local area network switching device is further configured to change a source address associated with the frame prior to forwarding the frame to the destination device so as to no longer reference the source device in an instance in which the security classification of the destination device is greater than the security classification of the source device such that a reply from the destination device that is received by the virtual local area network switching device is prevented from being forwarded to the source device.