如何在網關關閉前記錄淨流量何時關閉？

Question

我想每次在debian8上記錄網絡流量。
這是我的方式。

sudo vim /etc/systemd/system/graphical.target.wants/Ktraffic.service 

[Unit] 
Description=Record net traffic 

[Service] 
Type=oneshot 
ExecStart=/bin/bash /etc/init.d/K01trafficLog.sh 

[Install] 
WantedBy=poweroff.target 

sudo vim /etc/init.d/K011trafficLog.sh 
#!/bin/bash 
trafficlog="/var/log/traffic.log" 
echo `date "+%Y-%m-%d %H:%M:%S "` >> $trafficlog 
iptables -v -L INPUT |grep Chain >> $trafficlog 

systemctl enable ktraffic.service 

檢查流量日誌文件何時重新啓動。

sudo cat /var/log/traffic.log 
2017-02-05 10:49:31Chain INPUT (policy ACCEPT 0 packets, 0 bytes) 
2017-02-05 11:40:25Chain INPUT (policy ACCEPT 0 packets, 0 bytes) 

沒有包記錄在/var/log/traffic.log中。
在執行/etc/init.d/K011trafficLog.sh之前網絡連接已關閉，如何在網絡連接完成之前使其執行？

哪個服務在關機期間關閉了網絡連接？

systemctl |grep net - vim 
(standard input):sys-devices-pci0000:00-0000:00:1c.2-0000:03:00.0-net-eth0.device       loaded active plugged RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller 
(standard input):sys-subsystem-net-devices-eth0.device             loaded active plugged RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller 
(standard input):netfilter-persistent.service                loaded active exited netfilter persistent configuration 
(standard input):network-online.target                 loaded active active Network is Online 
(standard input):network.target                   loaded active active Network 
vim:sys-devices-pci0000:00-0000:00:1c.2-0000:03:00.0-net-eth0.device       loaded active plugged RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller 
vim:sys-subsystem-net-devices-eth0.device             loaded active plugged RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller 
vim:netfilter-persistent.service                loaded active exited netfilter persistent configuration 
vim:network-online.target                 loaded active active Network is Online 
vim:network.target                   loaded active active Network 

是否network.service在關機時關閉我的網絡？

sudo vim /etc/systemd/system/graphical.target.wants/Ktraffic.service 

[Unit] 
Description=Record net traffic 
Before=networking.service 

[Service] 
Type=oneshot 
ExecStart=/bin/bash /etc/init.d/K01trafficLog.sh 

[Install] 
WantedBy=poweroff.target 

要重新啓動測試它，我的問題仍然存在。
我在/ var/log/syslog中設置了一個標誌。

echo "it is a flag here to get output info of poweroff " | sudo tee -a /var/log/syslog 

重新啓動並獲取syslog如下。

[![enter image description here][1]][1] 

哪些服務結果信息開始同步硬件時鐘系統時鐘？

Answer 1

感謝FerencWágner。

solution to Execute simple script before shutdown and reboot

這是記錄在我的eth0網絡流量的權利fromat。

[Unit] 
Description=Record net traffic 
Before=shutdown.target reboot.target halt.target poweroff.target 

[Service] 
Type=oneshot 
RemainAfterExit=true 
ExecStart=/bin/bash 
ExecStop=/bin/bash /etc/init.d/K01trafficLog.sh 

[Install] 
WantedBy=poweroff.target shutdown.target reboot.target halt.target