vi /etc/systemd/system/obtain-ipv6.service[Unit] Description=Auto Obtain IPV6 Address After=network.target [Service] Type=simple ExecStart=/usr/bin/obtain-ipv6.sh start ExecStop=/usr/bin/obtain-ipv6.sh stop ExecReload=/usr/bin/obtain-ipv6.sh reload [Install] WantedBy=multi-user.targetsystemctl enable obtain-ipv6.servicevi /usr/bin/obtain-ipv6.sh#!/bin/bash if [ $1 == "start" ];then dhclient -6 ens3 elif [ $1 == "STOP" ];then dhclient -6 -r elif [ $1 == "reload" ];then dhclient -6 -r dhclient -6 ens3 fichmod u+x /usr/bin/obtain-ipv6.sh