Abstract: Methods, systems, and devices of the present disclosure are directed to providing seamless fault tolerant clock synchronization utilizing redundant reference clocks in a vehicle communication system. Redundant grandmaster clocks may be synchronized by utilizing clock signals sent between physical layers over a network, and derived clocks of network end devices may be synchronized using messages sent by the grandmaster clocks over the same or separate networks. The primary and backup grandmaster clocks may concurrently transmit synchronization messages to the network end devices. In this way, the grandmaster clocks may be synchronized to clock signals, and the network end devices may derive local clocks based on one, some, or all of the received messages transmitted over a network by the grandmaster clocks.