Ethernet link extension methods and devices provide, in one illustrative embodiment, an Ethernet link extender with physical medium attachment (PMA) circuits each having a transmitter and receiver that communicate with a respective node in a sequence of communication phases. The sequence includes at least an auto-negotiation phase and a subsequent training phase, the phases occurring simultaneously for both PMA circuits. In the auto-negotiation phase, the PMA circuits operate in a pass-through mode, rendering the extender transparent to the two nodes. In the training phase, the PMA circuits operate independently, sending training frames to their respective nodes based in part on received back-channel information and locally-determined training status information. The training phases may be prolonged if needed to provide a simultaneous transition to a frame-forwarding phase of the sequence.