# /etc/systemd/system/ptp4l-gm.service

[Unit]
Description=PTP Grandmaster on eth0
After=network-online.target chrony.service
Wants=network-online.target
Requires=chrony.service

[Service]
Type=simple
ExecStart=/usr/sbin/ptp4l -i eth0 -f /etc/linuxptp/ptp4l-gm.conf -m
Restart=always
RestartSec=3

[Install]
WantedBy=multi-user.target