Robust link synchronization in ethernet networks

An apparatus, comprising:

• a second network interface device for coupling the apparatus with a first network interface device via a network link, the second network interface device comprising a physical layer (PHY) processor, implemented on one or more integrated circuit (IC) devices, the PHY processor being configured to
• receive a first synchronization signal transmitted by the first network interface device during a synchronization phase of a link establishment process between the first network interface device and the second network interface device, the first synchronization signal being for training synchronization between the second network interface device and the first network interface device,
• in response to receiving the first synchronization signal from the first network interface device, transmit one or more initial synchronization response signals to the first network interface device during the synchronization phase, the one or more initial synchronization response signals being from among a fixed number of synchronization response signals that the second network interface device is configured to transmit to the first network interface device;
• after transmission of the one or more initial synchronization response signals and prior to completing the synchronization phase, receive a second synchronization signal from the first network interface device, and
• after receiving the second synchronization signal and prior to completing the synchronization phase, continue transmission of the fixed number of synchronization response signals to the first network interface device until the fixed number of synchronization response signals are transmitted from the second network interface device to the first network interface device.