PTP_CLASS_IPV4     39 include/linux/ptp_classify.h #define PTP_CLASS_V1_IPV4 (PTP_CLASS_V1 | PTP_CLASS_IPV4)
PTP_CLASS_IPV4     41 include/linux/ptp_classify.h #define PTP_CLASS_V2_IPV4 (PTP_CLASS_V2 | PTP_CLASS_IPV4)