NAME

       hwstamp_ctl - set time stamping policy at the driver level

SYNOPSIS

       hwstamp_ctl -i interface [ -r rx-filter ] [ -t tx-type ] [ -v ]

DESCRIPTION

       hwstamp_ctl  is  a  program  used  to set and get the hardware time stamping policy at the
       network driver level with the SIOCSHWTSTAMP ioctl(2).  The tx-type  and  rx-filter  values
       are hints to the driver what it is expected to do. If the requested fine-grained filtering
       for incoming packets is not supported, the driver  may  time  stamp  more  than  just  the
       requested types of packets.

       If  neither  tx-type  nor  rx-filter  values  are  passed  to the program, it will use the
       SIOCGHWTSTAMP ioctl(2) to  non-destructively  read  the  current  hardware  time  stamping
       policy.

       This  program  is  a  debugging  tool.  The ptp4l(8) program does not need this program to
       function, it will set the policy automatically as appropriate.

OPTIONS

       -i interface
              Specify the network interface of which the policy should be changed.

       -r rx-filter
              Specify which types of incoming packets should be time  stamped,  rx-filter  is  an
              integer value.

       -t tx-type
              Enable  or  disable  hardware  time  stamping  for  outgoing packets, tx-type is an
              integer value.

       -h     Display a help message and list of possible values for rx-filter and tx-type.

       -v     Prints the software version and exits.

SEE ALSO

       ioctl(2), ptp4l(8)