Linux Firewalls, Third Edition

Installing the Firewall

This section assumes that the firewall script is called rc.firewall. There's no reason that the script couldn't be called simply fwscript or something else either. In fact, on Debian systems the standard is closer to the single name, fwscript, rather than a name prefixed with an rc. as is the case on Red Hat. This section covers the commands as if the script was installed in either /etc/rc.d/ for a Red Hat or SUSE system and /etc/init.d/ for a Debian system.

As a shell script, initial installation is simple. The script should be owned by root. On Red Hat and SUSE:

chown root.root /etc/rc.d/rc.firewall

On Debian:

chown root.root /etc/init.d/rc.firewall

The script should be writable and executable by root alone. Ideally, ...