如何关闭time_wait连接
结合netstat和awk命令来统计网络连接数
From: http://hi.baidu.com/thinkinginlamp/blog/item/afbcab64b1ad81f3f6365453.html
netstat -n | awk '/^tcp/ {++state[$NF]} END {for(key in state) print key,"\t",state[key]}'
会得到类似下面的结果，具体数字会有所不同：
LAST_ACK 1
SYN_RECV 14
ESTABLISHED 79
FIN_WAIT1 28
FIN_WAIT2 3
CLOSING [...]
