[Unit] Description=Port-Knock Daemon After=network-online.target Wants=network-online.target Documentation=man:knockd(1) [Service] EnvironmentFile=-/etc/default/knockd ExecStart=/usr/sbin/knockd $KNOCKD_OPTS ExecReload=/bin/kill -HUP $MAINPID KillMode=mixed SuccessExitStatus=0 2 15 ProtectSystem=full CapabilityBoundingSet=CAP_NET_RAW CAP_NET_ADMIN CAP_SYS_MODULE [Install] WantedBy=multi-user.target