DDoS deflate+iptables防御轻量级ddos攻击

一.查看攻击者ip

#netstat -ntu | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n

二.安装ddos deflate

#wget http://www.inetbase.com/scripts/ddos/install.sh //下载DDoS deflate
#chmod 0700 install.sh //添加权限
#./install.sh //执行

三.配置DDoS deflate
下面是DDoS deflate的默认配置位于/usr/local/ddos/ddos.conf ，内容如下：

##### Paths of the script and other files
PROGDIR="/usr/local/ddos"
PROG="/usr/local/ddos/ddos.sh"
IGNORE_IP_LIST="/usr/local/ddos/ignore.ip.list"  //IP地址白名单
CRON="/etc/cron.d/ddos.cron"    //定时执行程序
APF="/etc/apf/apf"
IPT="/sbin/iptables"

##### frequency in minutes for running the script
##### Caution: Every time this setting is changed, run the script with --cron
#####          option so that the new frequency takes effect
FREQ=1   //检查时间间隔，默认1分钟

##### How many connections define a bad IP? Indicate that below.
NO_OF_CONNECTIONS=150     //最大连接数，超过这个数IP就会被屏蔽，一般默认即可

##### APF_BAN=1 (Make sure your APF version is atleast 0.96)
##### APF_BAN=0 (Uses iptables for banning ips instead of APF)
APF_BAN=1        //使用APF还是iptables。推荐使用iptables,将APF_BAN的值改为0即可。

##### KILL=0 (Bad IPs are'nt banned, good for interactive execution of script)
##### KILL=1 (Recommended setting)
KILL=1   //是否屏蔽IP，默认即可

##### An email is sent to the following address when an IP is banned.
##### Blank would suppress sending of mails
EMAIL_TO="root"   //当IP被屏蔽时给指定邮箱发送邮件，推荐使用，换成自己的邮箱即可

##### Number of seconds the banned ip should remain in blacklist.
BAN_PERIOD=600    //禁用IP时间，默认600秒，可根据情况调整

用户可根据给默认配置文件加上的注释提示内容，修改配置文件。

查看/usr/local/ddos/ddos.sh文件的第117行

netstat -ntu | awk ‘{print $5}’ | cut -d: -f1 | sort | uniq -c | sort -nr > $BAD_IP_LIST

修改为以下代码即可

netstat -ntu | awk ‘{print $5}’ | cut -d: -f1 | sed -n ‘/[0-9]/p’ | sort | uniq -c | sort -nr > $BAD_IP_LIST