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This article mainly introduces "the use of netstat commands in Linux". In daily operation, I believe many people have doubts about the use of netstat commands in Linux. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts about "the use of netstat commands in Linux". Next, please follow the editor to study!

Overall, the output of netstat can be divided into two parts:

One is Active Internet connections, which is called an active TCP connection, where "Recv-Q" and "Send-Q" refer to% 0A's receive queue and send queue. These numbers are generally supposed to be zero. If not, the package is piling up in the queue. This can only be seen in very rare cases.

The other is Active UNIX domain sockets, called the active Unix domain socket (like network sockets, but only for native communication, and performance can be doubled).

Proto shows the protocol used for the connection, RefCnt indicates the process number connected to this socket, Types shows the type of socket, State shows the current status of the socket, and Path indicates the path name used by other processes connected to the socket.

The netstat command is used to display statistics related to the IP, TCP, UDP, and ICMP protocols, and is generally used to verify the network connectivity of each port of the machine. Netstat is a program that accesses network and related information in the kernel. It can provide reports on TCP connection, TCP and UDP snooping, and process memory management.

If your computer sometimes receives datagrams that cause errors or failures, you should not be surprised that TCP/IP can allow these types of errors and automatically resend datagrams. But if the cumulative number of error cases accounts for a significant percentage of the IP datagrams received, or if its number is increasing rapidly, then you should use netstat to find out why these situations occur.

1. Command format:

Netstat [- acCeFghilMnNoprstuvVwx] [- A] [--ip]

2. Command function:

Netstat is used to display statistics related to IP, TCP, UDP and ICMP protocols, and is generally used to verify the network connectivity of each port of the machine.

3. Command parameters:

-an or-all displays the Socket in all connections.

-An or-lists the relevant addresses in the network type connection.

-c or-continuous continuously lists the network status.

-C or-cache displays the cache information configured by the router.

-e or-extend displays other relevant information about the network.

-F or-fib displays FIB.

-g or-groups displays the list of group members of the multi-broadcast function.

-h or-help online help.

-I or-interfaces displays a form of web interface information.

-l or-listening displays the Socket of the server in monitoring.

-M or-masquerade shows a camouflaged network connection.

-n or-numeric uses the IP address directly, not through the domain name server.

-N or-netlink or-symbolic displays the symbolic connection name of the network hardware peripheral.

-o or-timers displays the timer.

-p or-programs displays the program identification number and program name that are using Socket.

-r or-route displays Routing Table.

-s or-statistice displays statistical tables of network work information.

-t or-tcp displays the connection status of the TCP transport protocol.

-u or-udp shows the connection status of the UDP transport protocol.

-v or-verbose displays the instruction execution process.

-V or-version displays version information.

-w or-raw displays the connection status of the RAW transport protocol.

-x or-unix this parameter has the same effect as specifying the "- A unix" parameter.

-ip or-inet this parameter has the same effect as specifying the "- An inet" parameter.

4. Use an example:

List all tcp ports (both monitored and unmonitored)

List all tcp ports that are in the listening state

Display statistics for all ports

Displays the pid of processes that occupy a specific tcp port

Netstat-p can be used with other switches to add "PID/ process name" to the netstat output, so that it is easy to find programs running on specific ports for troubleshooting problems.

At this point, the study on "how to use the netstat command in Linux" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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