Start (X)Net/kissattach/slip at boot

I have written the startup script below so that all services are started. Now of course it is nice if this also happens when booting the server. First the start script.

Now I have created the following file in /etc/init.d with the name xnet.

Now it has to be added.
update-rc.d xnet defaults
update-rc.d xnet enable

Well, reboot and see if everything is alright.