文章目录

功能语法示例显示 tcp，udp 的端口和进程Show both listening and non-listening socketsList all tcp ports.List all udp portsList only listening portsList only listening TCP ports.List only listening UDP ports.List only the listening UNIX portsList the statistics for all ports.List the statistics for TCP (or) UDP ports.Display PID and program names in the output.Print the netstat information continuously.The kernel routing information.The port on which a program is running.Which process is using a particular port:

功能

netstat 命令用于显示各种网络相关信息，比如网络连接，路由表，接口状态 (Interface Statistics)，masquerade 连接，多播成员 Multicast Memberships等等

语法

列几个比较常用的

-t (tcp) 仅显示tcp相关选项-u (udp)仅显示udp相关选项-n 拒绝显示别名，能显示数字的全部转化为数字-l 仅列出在Listen(监听)的服务状态-p 显示建立相关链接的程序名

-a或–all：显示所有连线中的Socket；-A<网络类型>或–<网络类型>：列出该网络类型连线中的相关地址；-c或–continuous：持续列出网络状态；-C或–cache：显示路由器配置的快取信息；-e或–extend：显示网络其他相关信息；-F或–fib：显示FIB；-g或–groups：显示多重广播功能群组组员名单；-h或–help：在线帮助；-i或–interfaces：显示网络界面信息表单；-l或–listening：显示监控中的服务器的Socket；-M或–masquerade：显示伪装的网络连线；-n或–numeric：直接使用ip地址，而不通过域名服务器；-N或–netlink或–symbolic：显示网络硬件外围设备的符号连接名称；-o或–timers：显示计时器；-p或–programs：显示正在使用Socket的程序识别码和程序名称；-r或–route：显示Routing Table；-s或–statistice：显示网络工作信息统计表；-t或–tcp：显示TCP传输协议的连线状况；-u或–udp：显示UDP传输协议的连线状况；-v或–verbose：显示指令执行过程；-V或–version：显示版本信息；-w或–raw：显示RAW传输协议的连线状况；-x或–unix：此参数的效果和指定"-A unix"参数相同；–ip或–inet：此参数的效果和指定"-A inet"参数相同。

示例

显示 tcp，udp 的端口和进程

netstat -tunlp

这里我们简单科普一下网络连接状态State的含义 :

LISTEN：(Listening for a connection.)侦听来自远方的TCP端口的连接请求

SYN-SENT：(Active; sent SYN. Waiting for a matching connection request after having sent a connection request.)再发送连接请求后等待匹配的连接请求

SYN-RECEIVED：(Sent and received SYN. Waiting for a confirming connection request acknowledgment after having both received and sent connection requests.)再收到和发送一个连接请求后等待对方对连接请求的确认

ESTABLISHED：(Connection established.)代表一个打开的连接

FIN-WAIT-1：(Closed; sent FIN.)等待远程TCP连接中断请求，或先前的连接中断请求的确认

FIN-WAIT-2：(Closed; FIN is acknowledged; awaiting FIN.)从远程TCP等待连接中断请求

CLOSE-WAIT：(Received FIN; waiting to receive CLOSE.)等待从本地用户发来的连接中断请求

CLOSING：(Closed; exchanged FIN; waiting for FIN.)等待远程TCP对连接中断的确认

LAST-ACK：(Received FIN and CLOSE; waiting for FIN ACK.)等待原来的发向远程TCP的连接中断请求的确认

TIME-WAIT：(In 2 MSL (twice the maximum segment length) quiet wait after close. )等待足够的时间以确保远程TCP接收到连接中断请求的确认

CLOSED：(Connection is closed.)没有任何连接状态

Show both listening and non-listening sockets

# netstat -a | more : To show both listening and non-listening sockets.

List all tcp ports.

# netstat -at : To list all tcp ports.

List all udp ports

# netstat -au : To list all udp ports.

List only listening ports

# netstat -l : To list only the listening ports.

List only listening TCP ports.

# netstat -lt : To list only the listening tcp ports.

List only listening UDP ports.

# netstat -lu : To list only the listening udp ports.

List only the listening UNIX ports

# netstat -lx : To list only the listening UNIX ports

List the statistics for all ports.

# netstat -s : To list the statistics for all ports.

List the statistics for TCP (or) UDP ports.

# netstat -st(TCP) : To list the statistics for TCP ports.

# netstat -su(UDP) : List the statistics for UDP ports.

Display PID and program names in the output.

# netstat -pt : To display the PID and program names.

Print the netstat information continuously.

# netstat -c : To print the netstat information continuously.

The kernel routing information.

# netstat -r : To get the kernel routing information.

The port on which a program is running.

# netstat -ap | grep ssh : To get the porton which a program is running.

Which process is using a particular port:

# netstat -an | grep ':80' : To get the processwhich is using the given port.