Linux防火墙iptables简明教程

#允许本机访问
iptables -A INPUT -s 127.0.0.1 -d 127.0.0.1 -j ACCEPT
# 允许已建立的或相关连的通行
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
#允许所有本机向外的访问
iptables -A OUTPUT -j ACCEPT
# 允许访问22端口
iptables -A INPUT -p tcp --dport 22 -j ACCEPT
#允许访问80端口
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
#允许FTP服务的21和20端口
iptables -A INPUT -p tcp --dport 21 -j ACCEPT
iptables -A INPUT -p tcp --dport 20 -j ACCEPT
#如果有其他端口的话，规则也类似，稍微修改上述语句就行
#禁止其他未允许的规则访问
iptables -A INPUT -j REJECT
iptables -A FORWARD -j REJECT

#!/bin/sh
# Filename: block_ip.sh
# Purpose: blocks all IP address/network found in a text file
# The text file must have one IP address or network per line
#################################################################
# Change the following path/filename to match yours
IP_LIST_FILE=/path/to/ip.txt
#################################################################
# Don't change anything below unless you are a smarty pant!
#################################################################
IPTABLES_BIN=/sbin/iptables
# Get the IP address/network from the file and ignore any line starting with # (comments)
BAD_IP_ADDR_LIST=$(grep -Ev "^#" $IP_LIST_FILE)
# Now loop through the IP address/network list and ban them using iptabels
for i in $BAD_IP_ADDR_LIST
do
echo -n "Blocking $i ...";
$IPTABLES_BIN -A INPUT -s $i -j DROP
$IPTABLES_BIN -A OUTPUT -d $i -j DROP
echo "DONE.";
done
##################################################################
# END OF SCRIPT - NOTHING TO SEE HERE - THAT'S ALL FOLKS!
##################################################################