CentOS服务器iptables配置简单教程

iptables -P INPUT ACCEPT
iptables -F
iptables -A INPUT -i lo -j ACCEPT
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
iptables -P INPUT DROP
iptables -P FORWARD DROP
iptables -P OUTPUT ACCEPT
iptables -L -v

#!/bin/sh
IPTABLES=/sbin/iptables



# clear
$IPTABLES -F

# if pkg type is allow, then accept
#$IPTABLES -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT



# 如果同时在80端口的连接数大于10，就Drop掉这个ip

netstat -an | grep :80 | awk -F: '{ print $8 }' | sort | uniq -c | awk -F\  '$1>10 && $2!="" { print $2 }' >> /etc/fw.list
less /etc/fw.list | sort | uniq -c | awk -F\  '$2!="" { print $2 }' > /etc/fw.list2
less /etc/fw.list2 > /etc/fw.list
while read line

    do
    t=`echo "$line"`
    $IPTABLES -A INPUT -p tcp -s $t -j DROP
done  /proc/sys/net/ipv4/ip_forward

$IPTABLES -P INPUT DROP
$IPTABLES -P FORWARD DROP
$IPTABLES -P OUTPUT DROP
$IPTABLES -F
$IPTABLES -X


$IPTABLES -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
$IPTABLES -A INPUT -p tcp --dport 22 -j ACCEPT
$IPTABLES -A INPUT -p tcp --dport 80 --tcp-flags SYN,ACK,FIN,RST SYN -m limit --limit 30/m --limit-burst 2 -j ACCEPT


$IPTABLES -A OUTPUT -p tcp -s 127.0.0.1 -j ACCEPT
$IPTABLES -A OUTPUT -p tcp -s 192.168.1.102 -j ACCEPT
$IPTABLES -A OUTPUT -p udp -s 127.0.0.1 -j ACCEPT
$IPTABLES -A OUTPUT -p udp -s 192.168.1.102 -j ACCEPT



$IPTABLES -A INPUT -p tcp --syn -j DROP