Iptables Tutorial 1.1.19

Andreasson Oskar

# 4.2.1 Set policies

#

#

# 4.2.2 Create user specified chains

#

#

# 4.2.3 Create content in user specified chains

#

#

# 4.2.4 PREROUTING chain

#

#

# 4.2.5 POSTROUTING chain

#

#

# Enable simple IP Forwarding and Network Address Translation

#

$IPTABLES -t nat -A POSTROUTING -o $INET_IFACE -j SNAT –to-source $INET_IP

#

# 4.2.6 OUTPUT chain

#

######

# 4.3 mangle table

#

#

# 4.3.1 Set policies

#

#

# 4.3.2 Create user specified chains

#

#

# 4.3.3 Create content in user specified chains

#

#

# 4.3.4 PREROUTING chain

#

#

# 4.3.5 INPUT chain

#

#

# 4.3.6 FORWARD chain

#

#

# 4.3.7 OUTPUT chain

#

#

# 4.3.8 POSTROUTING chain

#

I.4.

Пример rc.DHCP.firewall

#!/bin/sh

#

# rc.firewall – DHCP IP Firewall script for Linux 2.4.x and iptables

#

# Copyright (C) 2001 Oskar Andreasson <bluefluxATkoffeinDOTnet>

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; version 2 of the License.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program or from the site that you downloaded it

# from; if not, write to the Free Software Foundation, Inc., 59 Temple

# Place, Suite 330, Boston, MA 02111-1307 USA

#

###########################################################################

#

# 1. Configuration options.

#

#

# 1.1 Internet Configuration.

#

INET_IFACE="eth0"

#

# 1.1.1 DHCP

#

#

# Information pertaining to DHCP over the Internet, if needed.

#

# Set DHCP variable to no if you don't get IP from DHCP. If you get DHCP

# over the Internet set this variable to yes, and set up the proper IP

# address for the DHCP server in the DHCP_SERVER variable.

#

DHCP="no"

DHCP_SERVER="195.22.90.65"

#

# 1.1.2 PPPoE

#

# Configuration options pertaining to PPPoE.

#

# If you have problem with your PPPoE connection, such as large mails not

# getting through while small mail get through properly etc, you may set

# this option to

«yes» which may fix the problem. This option will set a

# rule in the PREROUTING chain of the mangle table which will clamp

# (resize) all routed packets to PMTU (Path Maximum Transmit Unit).

#

# Note that it is better to set this up in the PPPoE package itself, since

# the PPPoE configuration option will give less overhead.

#

PPPOE_PMTU="no"

#

# 1.2 Local Area Network configuration.

#

# your LAN's IP range and localhost IP. /24 means to only use the first 24

# bits of the 32 bit IP address. the same as netmask 255.255.255.0

#

LAN_IP="192.168.0.2"

LAN_IP_RANGE="192.168.0.0/16"

LAN_IFACE="eth1"

#

# 1.3 DMZ Configuration.

#

#

# 1.4 Localhost Configuration.

#

LO_IFACE="lo"

LO_IP="127.0.0.1"

#

# 1.5 IPTables Configuration.

#

IPTABLES="/usr/sbin/iptables"

#

# 1.6 Other Configuration.

#

###########################################################################

#

# 2. Module loading.

#

#

# Needed to initially load modules

#

/sbin/depmod -a

#

# 2.1 Required modules

#

/sbin/modprobe ip_conntrack

/sbin/modprobe ip_tables

/sbin/modprobe iptable_filter

/sbin/modprobe iptable_mangle

/sbin/modprobe iptable_nat

/sbin/modprobe ipt_LOG

/sbin/modprobe ipt_limit

/sbin/modprobe ipt_MASQUERADE

#

# 2.2 Non-Required modules

#

#/sbin/modprobe ipt_owner

#/sbin/modprobe ipt_REJECT

#/sbin/modprobe ip_conntrack_ftp

#/sbin/modprobe ip_conntrack_irc

#/sbin/modprobe ip_nat_ftp

#/sbin/modprobe ip_nat_irc