[Unit]
Description=%i DHCP Client v6
IgnoreOnIsolate=yes
DefaultDependencies=no
Conflicts=shutdown.target

[Service]
Restart=always
RestartPreventExitStatus=0
Type=simple
PIDFile=/tmp/dhclient6-%i.pid
ExecStartPre=/usr/syno/lib/systemd/scripts/dhclient6.sh pre-start %i
ExecStart=/usr/syno/lib/systemd/scripts/dhclient6.sh start %i
ExecStartPost=/usr/syno/lib/systemd/scripts/dhclient6.sh post-start %i
ExecStopPost=/usr/syno/lib/systemd/scripts/dhclient6.sh post-stop %i

[X-Synology]