Unidirectional fast retraining of a bidirectional ethernet link

A PHY device in an Ethernet network in a vehicle includes a transceiver and a processor. The transceiver communicates with a peer PHY over a bidirectional Ethernet link in the vehicle, the transceiver supports communication modes that are separately configurable for transmission and reception, and are selected from (i) a data mode for communication of data, and (ii) a retraining mode for recovering from reception failure, and reception of retraining signals in the retraining mode is less sensitive to interference than reception of data signals in the data mode. The processor sets the transceiver for data mode transmission to, and data mode reception from the peer PHY, and in response to detecting that during data mode reception a reception quality has degraded to below a specified threshold, set the transceiver to reception in the retraining mode while concurrently transmitting to the peer PHY in the data mode.