CLOSING 服务器端和客户端都同时关闭连接
CLOSE_WAIT 等待关闭连接
TIME_WAIT The socket is waiting after close to handle packets still in the network. 表示收到了对方的FIN报文,并发送出了ACK报文,等待2MSL后就可回到CLOSED状态
LAST_ACK The remote end has shut down, and the socket is closed. Waiting for acknowledgement. 远端关闭,当前socket被动关闭后发送FIN报文,等待对方ACK报文
LISTEN 监听状态
SYN_RECV 接收到SYN报文
SYN_SENT 已经发送SYN报文
FIN_WAIT1 The socket is closed, and the connection is shutting down
FIN_WAIT2 Connection is closed, and the socket is waiting for a shutdown from the remote end.
2.监控脚本编写
tcp_connection_status.sh
#!/bin/bash
#this script is used to get tcp and udp connetion status
#tcp status
metric=$1
tmp_file=/tmp/tcp_status.txt
/bin/netstat -an|awk '/^tcp/{++S[$NF]}END{for(a in S) print a,S[a]}' > $tmp_file
case $metric in
closed)
output=$(awk '/CLOSED/{print $2}' $tmp_file)
if [ "$output" == "" ];then
echo 0
else
echo $output
fi
;;
listen)
output=$(awk '/LISTEN/{print $2}' $tmp_file)
if [ "$output" == "" ];then
echo 0
else
echo $output
fi
;;
synrecv)
output=$(awk '/SYN_RECV/{print $2}' $tmp_file)
if [ "$output" == "" ];then
echo 0
else
echo $output
fi
;;
synsent)
output=$(awk '/SYN_SENT/{print $2}' $tmp_file)
if [ "$output" == "" ];then
echo 0
else
echo $output
fi
;;
established)
output=$(awk '/ESTABLISHED/{print $2}' $tmp_file)
if [ "$output" == "" ];then
echo 0
else
echo $output
fi
;;
timewait)
output=$(awk '/TIME_WAIT/{print $2}' $tmp_file)
if [ "$output" == "" ];then
echo 0
else
echo $output
fi
;;
closing)
output=$(awk '/CLOSING/{print $2}' $tmp_file)
if [ "$output" == "" ];then
echo 0
else
echo $output
fi
;;
closewait)
output=$(awk '/CLOSE_WAIT/{print $2}' $tmp_file)
if [ "$output" == "" ];then
echo 0
else
echo $output
fi
;;
lastack)
output=$(awk '/LAST_ACK/{print $2}' $tmp_file)
if [ "$output" == "" ];then
echo 0
else
echo $output
fi
;;
finwait1)
output=$(awk '/FIN_WAIT1/{print $2}' $tmp_file)
if [ "$output" == "" ];then
echo 0
else
echo $output
fi
;;
finwait2)
output=$(awk '/FIN_WAIT2/{print $2}' $tmp_file)
if [ "$output" == "" ];then
echo 0
else
echo $output
fi
;;
*)
echo -e "\e[033mUsage: sh $0 [closed|closing|closewait|synrecv|synsent|finwait1|finwait2|listen|established|lastack|timewait]\e[0m"
esac