我的服务器的iptables，大家指导一下！
环境：red9，最近老不稳定，郁闷急了，我又是新手，一时不知道从何下手，eth0和eth1，其中eth0是内网，eth1是外网固定ip上网（无路由）内部计算机通过eth0做dhcp共享上网（够垃圾的吧）服务器同时提供
dhcpd给内网上网
sendmail公司员工邮件
httpd只有htm静态页
named我判断过了公司域名www的不通过这走，mail的通过这走
iptables简单的防火墙，在此我贴出iptables的链，请各位指导一下！
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#!/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.
#
###########################################################################
#
# 1. Configuration options.
#
#
# 1.1 Internet Configuration.
#
INET_IFACE="eth1"
#
# 1.2 DHCP
#
#
DHCP="no"
DHCP_SERVER="192.168.0.1"
#
# 1.3 Local Area Network configuration.
#
#
LAN_IP="192.168.0.1"
LAN_IP_RANGE="192.168.0.0/24"
LAN_IFACE="eth0"
#
#
# 1.4 Localhost Configuration.
#
LO_IFACE="lo"
LO_IP="127.0.0.1"
#
# 1.5 IPTables Configuration.
#
IPTABLES="/sbin/iptables"
#
###########################################################################
#
# 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_state
/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
###########################################################################
#
# 3. /proc set up.
#
#
# 3.1 Required proc configuration
#
echo "1" > /proc/sys/net/ipv4/ip_forward
###########################################################################
#
# 4. rules set up.
#
$IPTABLES -F
$IPTABLES -X
$IPTABLES -F -t mangle
$IPTABLES -t mangle -X
$IPTABLES -F -t nat
$IPTABLES -t nat -X
######
# 4.1 Filter table
#
# 4.1.1 Set policies
#
#$IPTABLES -P INPUT DROP
#$IPTABLES -P OUTPUT DROP
#$IPTABLES -P FORWARD DROP
$IPTABLES -P INPUT ACCEPT
$IPTABLES -P OUTPUT ACCEPT
$IPTABLES -P FORWARD ACCEPT
#
#4.1.2 Create chain for bad tcp packets
#
$IPTABLES -N bad_tcp_packets
#
# 4.1.3Create separate chains for ICMP, TCP and UDP to traverse
#
$IPTABLES -N allowed
$IPTABLES -N tcp_packets
$IPTABLES -N udp_packets
$IPTABLES -N icmp_packets
#
# 4.1.4 Create content in userspecified chains
#
#
# bad_tcp_packets chain
#
$IPTABLES -A bad_tcp_packets -p tcp --tcp-flags SYN,ACK SYN,ACK -m state --state NEW -j REJECT --reject-with tcp-reset
#$IPTABLES -A bad_tcp_packets -p tcp ! --syn -m state --state NEW -j LOG --log-prefix "New not syn:"
$IPTABLES -A bad_tcp_packets -p tcp ! --syn -m state --state NEW -j DROP
#
# allowed chain
#
$IPTABLES -A allowed -p TCP --syn -j ACCEPT
$IPTABLES -A allowed -p TCP -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPTABLES -A allowed -p TCP -j DROP
#
# TCP rules
#
$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 25 -j allowed
$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 110 -j allowed
$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 80 -j allowed
$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 113 -j allowed
#
# UDP ports
#
$IPTABLES -A udp_packets -p UDP -s 0/0 --source-port 53 -j ACCEPT
if [ $DHCP == "yes" ] ; then
$IPTABLES -A udp_packets -p UDP -s $DHCP_SERVER --sport 67 --dport 68 -j ACCEPT
#
#
# In Microsoft Networks you will be swamped by broadcasts. These lines
# will prevent them from showing up in the logs.
#
$IPTABLES -A udp_packets -p UDP -i $INET_IFACE --destination-port 135:139 -j DROP
#
# If we get DHCP requests from the Outside of our network, our logs will
# be swamped as well. This rule will block them from getting logged.
#
$IPTABLES -A udp_packets -p UDP -i $INET_IFACE -d 255.255.255.255 --destination-port 67:68 -j DROP
#
######### wxb insert begin #########
# Trust the Loop
$IPTABLES -A INPUT -i lo -j ACCEPT
$IPTABLES -A OUTPUT -o lo -j ACCEPT
# Trust the inside network card
$IPTABLES -A INPUT -i eth0 -j ACCEPT
$IPTABLES -A OUTPUT -o eth0 -j ACCEPT
$IPTABLES -A OUTPUT -o eth1 -p icmp -j ACCEPT
$IPTABLES -A INPUT -i eth1 -p icmp --icmp-type echo-reply -j ACCEPT
$IPTABLES -A INPUT -i eth1 -p icmp --icmp-type echo-request -j DROP
$IPTABLES -A INPUT -i eth1 -p TCP --dport telnet -j DROP
$IPTABLES -A INPUT -i eth1 -p UDP --dport telnet -j DROP
$IPTABLES -A INPUT -i eth1 -p TCP --dport ftp -j DROP
$IPTABLES -A INPUT -i eth1 -p UDP --dport ftp -j DROP
######### wxb insert end #########
#
# 4.1.5 INPUT chain
#
#
# Bad TCP packets we don't want.
#
$IPTABLES -A INPUT -p tcp -j bad_tcp_packets
#
# Rules for special networks not part of the Internet
$IPTABLES -A INPUT -p ALL -i $LAN_IFACE -s $LAN_IP_RANGE -j ACCEPT
$IPTABLES -A INPUT -p ALL -i $LO_IFACE -j ACCEPT
#
# Special rule for DHCP requests from LAN, which are not caught properly
# otherwise.
#
$IPTABLES -A INPUT -p UDP -i $LAN_IFACE --dport 67 --sport 68 -j ACCEPT
#
# Rules for incoming packets from the internet.
#
ESTABLISHED,RELATED -j LOG --log-prefix "Incoming Package: "
$IPTABLES -A INPUT -p ALL -i $INET_IFACE -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPTABLES -A INPUT -p TCP -i $INET_IFACE -j tcp_packets
$IPTABLES -A INPUT -p UDP -i $INET_IFACE -j udp_packets
$IPTABLES -A INPUT -p ICMP -i $INET_IFACE -j icmp_packets
#
# Rules for incoming email
#
$IPTABLES -A INPUT -i $INET_IFACE -p tcp -s 0/0 --sport 1024:65535 -d $LAN_IP --dport 25 -j ACCEPT
$IPTABLES -A OUTPUT -o $INET_IFACE -p tcp ! --syn -s 0/0 --sport 25 -d any/0 --dport 1024:65535 -j ACCEPT
#
#
# 4.1.6 FORWARD chain
#
#
# Bad TCP packets we don't want
#
$IPTABLES -A FORWARD -p tcp -j bad_tcp_packets
#
# Accept the packets we actually want to forward
#
$IPTABLES -A FORWARD -i $LAN_IFACE -j ACCEPT
$IPTABLES -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
#
#
# 4.1.7 OUTPUT chain
#
#
$IPTABLES -A OUTPUT -p tcp -j bad_tcp_packets
#
# Special OUTPUT rules to decide which IP's to allow.
#
$IPTABLES -A OUTPUT -p ALL -s $LO_IP -j ACCEPT
$IPTABLES -A OUTPUT -p ALL -s $LAN_IP -j ACCEPT
$IPTABLES -A OUTPUT -p ALL -o $INET_IFACE -j ACCEPT
#
######
# 4.2 nat table
#
# 4.2.1 POSTROUTING chain
#
if [ $PPPOE_PMTU == "yes" ] ; then
$IPTABLES -t nat -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
fi
$IPTABLES -t nat -A POSTROUTING -o $INET_IFACE -j MASQUERADE
#
##################################
###################################
#以下没用的我都没写。
请各位都给过过眼我的防火墙起作用了吗（当然是防护作用了）非常感谢！
