README from source package says:
When installing ufw from source, you will also need to integrate it into your boot process for the firewall to start when you restart your system. Depending on your needs, this can be as simple as adding the following to a startup script (eg rc.local for systems that use it): # /lib/ufw/ufw-init start For systems that use SysV initscripts, an example script is provided in doc/initscript.example. See doc/upstart.example for an Upstart example. Consult your distribution's documentation for the proper way to modify your boot process.
On my system I have this:
# /etc/ufw/ufw.conf # # Set to yes to start on boot. If setting this remotely, be sure to add a rule # to allow your remote connection before starting ufw. Eg: 'ufw allow 22/tcp' ENABLED=yes
So, why does simple iptables rule manager need to be started at boot time? Is there any secret to that, or it merely checks if all rules are in place ?