[Linux] 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! 
##################################################################