使用netstat命令，查看VPS当前链接确认是否受到攻击：
# netstat -an | grep 80|awk '{printf "%s %s\n",$5,$6}'|sort
第一栏是客户机IP和端口，第二栏是连接状态
如果来自同一IP的连接很多（超过50个），而且都是连续端口，就很可能是攻击
如果来自同一IP的连接很多（超过50个），而且都是连续端口，就很可能是攻击
可以使用iptables直接BAN了这个IP的永久访问：
/sbin/iptables -A INPUT -s 12.34.56.78 -j DROP
下面开始安装DDos deflat
wget http://www.inetbase.com/scripts/ddos/install.sh
chmod +x install.sh
./install.sh
chmod +x install.sh
./install.sh
修改配置 vi /usr/local/ddos/ddos.conf
———————————————————————————————————————————-##### 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 ——————————————————————————————————————–
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 ——————————————————————————————————————–
APF_BAN=1要设置成0，因为要使用iptables来封某些可疑连接EMAIL_TO="mutnyaye@gmail.com"
第四步:禁止ping
输入 /sbin/ifconfig 常看网卡,一般都是 venet0,可以确认一下,下面的venet0改成相应的网卡名称
输入
/sbin/iptables -A OUTPUT -o venet0 -p icmp -j ACCEPT
/sbin/iptables -A INPUT -i venet0 -p icmp –icmp-type echo-reply -j ACCEPT
/sbin/iptables -A INPUT -i venet0 -p icmp –icmp-type echo-request -j DROP
/sbin/service iptables save
/sbin/iptables -A INPUT -i venet0 -p icmp –icmp-type echo-reply -j ACCEPT
/sbin/iptables -A INPUT -i venet0 -p icmp –icmp-type echo-request -j DROP
/sbin/service iptables save
OK,简单的防护已经有了,最后重启一下的VPS就行了
