Iptables firewall configuration instance

#! /Bin/sh # The following are network information about the firewall # internal network adapter: eth1 # internal IP address: 192.168.1.1 # internal subnet mask: 255.255.255.0 # internal network segment: 192.168.1.0/24 # internal Nic: eth0 # internal IP address: 24.68.32.118 # internal subnet mask: 255.255.252.0 #*************#! /Bin/sh
# The Network information about the firewall is as follows:
# Internal Nic: eth1
# Internal IP address: 192.168.1.1
# Internal subnet mask: 255.255.255.0
# Internal network segment: 192.168.1.0/24
# Internal Nic: eth0
# Internal IP address: 24.68.32.118
# Internal subnet mask: 255.255.252.0
#*************************************
# Save the current settings to/etc/sysconfig/ Iptables
# Use/etc/rc. d/init. d/iptables save
# Or/sbin/service iptables save
#*************************************
# Using IP Forwarding
Echo 1>/proc/sys/net/ipv4/ip_forward
# Clear original settings
Iptables-F
Iptables-X
Iptables-F-t mangle
Iptables-t mangle-X
Iptables-F-t nat
Iptables-t nat-X
# Set Filter Table default rules
Iptables-P INPUT ACCEPT
Iptables-P OUTPUT ACCEPT
Iptables-P FORWARD ACCEPT
# Enable NAT
Iptables-t nat-a postrouting-o eth0-j SNAT -- to-source24.68.32.118
# Enable external address translation
# All connections to 24.68.32.118: 8080 are forwarded to 192.168.1.5: 80.
Iptables-t nat-a prerouting-p tcp-d 24.68.32.118 -- dport8080-j DNAT -- to 192.168.1.5: 80
######################################## #####
# The following are successfully configured instances in the lab:
/*
Modprobe ip_tables
Modprobe ip_nat_ftp
Modprobe ip_nat_irc
Modprobe ip_conntrack
Modprobe ip_conntrack_ftp
Modprobe ip_conntrack_irc
/Sbin/iptables-F
/Sbin/iptables-X
/Sbin/iptables-Z
/Sbin/iptables-F-t nat
/Sbin/iptables-X-t nat
/Sbin/iptables-Z-t nat
/Sbin/iptables-P INPUT ACCEPT
/Sbin/iptables-P OUTPUT ACCEPT
/Sbin/iptables-P FORWARD ACCEPT
/Sbin/iptables-t nat-P PREROUTING ACCEPT
/Sbin/iptables-t nat-P POSTROUTING ACCEPT
/Sbin/iptables-t nat-P OUTPUT ACCEPT
Iptables-t nat-a postrouting-s 192.168.1.0/24-jMASQUERADE
*/