Edit File: ptp.xml
<?xml version="1.0" encoding="utf-8"?> <service> <short>Precision Time Protocol (PTP) Master</short> <description>The Precision Time Protocol (PTP) allows to synchronize computers to a time master. Enable this option, if you are providing a PTP master. You need the linuxptp package installed for this option to be useful.</description> <port protocol="udp" port="319"/> <port protocol="udp" port="320"/> </service>