An operation method of a communication node in an Ethernet-based vehicle network, the communication node including a regulator, a physical (PHY) layer unit, and a processor, includes outputting, by the processor, a first signal to initiate a supply of power to the communication node; outputting, by the processor, a second signal to initiate a transition of the communication node from a normal mode to a sleep mode; and transitioning, by the PHY layer unit, the communication node from the normal mode to the sleep mode when the second signal is received at the PHY layer unit from the processor.