The object provides a way to prevent HOL (Head Of Line) blocking between ports. HOL protection may prevent forwarding a packet to a blocking port.The idea relies on the assumption that it is better to discard packets destined to blocking ports, then to let them consume more and more buffers in the input-port's Rx-counters because eventually these input ports may become totally blocked. The value enabled(3) indicates that HOL function is enabled on this port, as long as swDevCtrlHOLState is also enabled for this device. When disabled(2) but swDevCtrlHOLState is still enabled for the device, HOL function is disabled on this port. The meanings of the values are: other(1) - this entry is currently in use but the conditions under which it will remain so are different from each of the following values. disabled(2) - HOL function disable. enabled(3) - HOL function enable.