i /etc/sysctl.confcookie
编辑文件,加入如下内容:
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_fin_timeout = 30 socket
而后执行/sbin/sysctl -p让参数生效。tcp
net.ipv4.tcp_syncookies = 1表示开启SYN Cookies。当出现SYN等待队列溢出时,启用cookies来处理,可防范少许SYN攻击,默认为0,表示关闭;队列
net.ipv4.tcp_tw_reuse = 1表示开启重用。容许将TIME-WAIT sockets从新用于新的TCP链接,默认为0,表示关闭;ip
net.ipv4.tcp_tw_recycle = 1表示开启TCP链接中TIME-WAIT sockets的快速回收,默认为0,表示关闭。cookies
net.ipv4.tcp_fin_timeout修改系統默认的TIMEOUT时间grep
修改以后,再用命令查看TIME_WAIT链接数netstat -ant |grep “TIME_WAIT” |wc –l
im