.. index:: pair: group; Use ptp4l to synchronize clocks
.. _doxid-group__ptp-ptp4l:

Use ptp4l to synchronize clocks
===============================

.. toctree::
	:hidden:

Check that ptp4l can be used to synchronize clocks across network.

#. Find out PTP device associated with the IUT interface, call **open()** to get its FD.

#. Find out PTP device associated with the Tester interface, call **open()** to get its FD.

#. Check that **ptp4l** is available on IUT and Tester.

#. Disable **NTP** daemon on IUT and Tester.

#. Use **clock_settime()** on IUT and Tester to set different initial values for IUT and Tester clocks.

#. Run **ptp4l** as master on Tester.

#. Run **ptp4l** as slave on IUT.

#. Wait for a while and terminate **ptp4l** on IUT and Tester.

#. Check whether anything was printed to stderr on IUT.

#. Obtain current time on the IUT clock and on the Tester clock, check that obtained values are (approximately) equal.



.. rubric:: Parameters:

.. list-table::
	:widths: 20 80

	*
		- env

		- 
		  Testing environment:
		  
		  * :ref:`env.peer2peer <doxid-group__env-peer2peer>`