This is the configuration script file for our Mail Server. This is configured to allows unlimited traffic on the Loopback interface, ICMP, DNS Server and Client (53), SSH Server (22), SMTP Server and Client (25), IMAP server (143), and OUTGOING TRACEROUTE requests by default.

　　If you don't want some services listed in the firewall rules files for the Mail Server that I make ON by default, comment them out with a "#" at the beginning of the line. If you want some other

　　services that I commented out with a "#", then remove the "#" at the beginning of their lines.

　　Create the firewall script file, touch /etc/rc.d/init.d/firewall on your Mail Server and add:

　　#!/bin/sh

　　#

　　# ----------------------------------------------------------------------------

　　# Last modified by Gerhard Mourani: 04-25-2000

　　# ----------------------------------------------------------------------------

　　# Copyright (C) 1997, 1998, 1999 Robert L. Ziegler

　　#

　　# Permission to use, copy, modify, and distribute this software and its

　　# documentation for educational, research, private and non-profit purposes,

　　# without fee, and without a written agreement is hereby granted.

　　# This software is provided as an example and basis for individual firewall

　　# development. This software is provided without warranty.

　　#

　　# Any material furnished by Robert L. Ziegler is furnished on an

　　# "as is" basis. He makes no warranties of any kind, either expressed

　　# or implied as to any matter including, but not limited to, warranty

　　# of fitness for a particular purpose, exclusivity or results obtained

　　# from use of the material.

　　# ----------------------------------------------------------------------------

　　#

　　# Invoked from /etc/rc.d/init.d/firewall.

　　# chkconfig: - 60 95

　　# description: Starts and stops the IPCHAINS Firewall

　　# used to provide Firew