Patent ID: 8493840

Claim:
A fault-tolerant device configured to communicate on an Ethernet network, the Ethernet network having a beacon device configured to periodically generate a beacon packet, the fault-tolerant device comprising: a processor; a first port and a second port connectable to the Ethernet network, each port using a common Media Access Control (MAC) address; and an Ethernet interface circuit comprising: a port selection circuit to selectively connect one of the ports between the processor and the Ethernet network for transmitting data, a beacon detection circuit in communication with each of the ports and configured to periodically receive the beacon packet from each of the ports, wherein the beacon detection circuit identifies one of the ports as failed when the beacon packet is not received at the identified port within a predefined timeout period, and an error detection circuit connected to each of the ports to concurrently detect a fault on the Ethernet network with either the first port or the second port regardless of which of the ports is enabled by the port selection circuit, wherein upon detection of a fault on the port connected between the processor and the Ethernet network for transmitting data, the port selection circuit switchably connects the other of the ports without remapping the MAC address.