Hi
Here some short howto config systemd to run sysvinit firewall script:
1st copy your existing iptables script to
cp myfw /root/bin/myfw
chmod 750 /root/bin/myfw
Now lets create the systemd service as following:
vim /etc/systemd/system/myfw.service
[Unit] Description=myfw After=network.target [Service] RemainAfterExit=yes ExecStart=/root/bin/myfw start ExecStop=/root/bin/myfw stop User=root [Install] WantedBy=multi-user.target
Enable the script for autostart at boot
systemctl enable myfw.service
Start the firewall
systemctl start myfw.service
Have fun!