This read-create enumerated object sets the operating mode of this PTP (IEEE 1588) clock: master(1), slave(2), boundary(3), transparent(4), or forward(5), defaulting to slave. An admin sets this to define the device's role in the PTP time-distribution hierarchy on a given interface, such as slaving to an upstream grandmaster or acting as a boundary clock between domains. For example, an admin sets this to boundary(3) on a device that must both receive PTP time from an upstream master and redistribute it to downstream slaves in another domain.