Patent ID: 8590033

Claim:
A method for securely communicating process control data via a process control network comprising: discovering a network device that is communicatively connected to the process control network; removing one or more authorized physical addresses that each correspond to a valid node of the process control network from an address resolution protocol table or a forwarding database table of the network device; transferring the removed authorized physical addresses to a static address table of the network device, wherein authorized physical addresses at the static address table do not age; suspending one or more bridging functions of the network device, wherein the bridging functions include address learning, aging, and forwarding for the address resolution protocol table or the forwarding database table of the network device; processing a frame received at the network device if the frame includes an authorized physical address that corresponds to an address of the static address table; and dropping the received frame if the frame includes an unauthorized physical address that does not correspond to an address of the static address table.