-c, --continuous
This will cause netstat to print the selected information every second continuously（连续不断的）.
-e, --extend
Display additional information. Use this option twice for maximum detail.
显示更多的信息，用-ee 显示最多的信息
-o, --timers
Include information related to networking timers.
显示和网络计时器相关的信息
-p, --program
Show the PID and name of the program to which each socket belongs.
显示连接所属的PID和程序名称
-l, --listening
Show only listening sockets. (These are omitted by default.)
只显示监听的套接字（端口）默认是忽略这个选项的
-a, --all
Show both listening and non-listening (for TCP this means established connections) sockets. With the --interfaces option, show interfaces that are not marked
-F
Print routing information from the FIB. (This is the default.)
-C
Print routing information from the route cache.
-Z --context
If SELinux enabled print SELinux context.
-T --notrim
Stop trimming long addresses.
delay
Netstat will cycle printing through statistics every delay seconds
接下来是重头戏了，深入理解netstat的输出，这里才是实际能帮助我们、给我们提示的地方。