Shulou(Shulou.com)06/02 Report--

This article is about how linux looks at ports. The editor thought it was very practical, so I shared it with you as a reference. Let's follow the editor and have a look.

The command for linux to view the port: 1, [a] shows all connections and monitoring ports of the machine; 2, [n] the form of network IP address, shows the currently established valid connection and port; 3, [r] displays routing table information; 4, [s] displays statistical information by protocol; 5, [v] shows the current valid connection.

Linux commands to view ports:

The first kind:

Lsof-I: Port number

The second kind:

Netstat-nltp | grep port number

-a: displays all connected and monitored ports on this machine

-n: the form of the network IP address, showing the currently established valid connections and ports

-r: displays routing table information

-s: displays statistics by protocol

-v: displays currently valid connections

-t: displays all TCP protocol connections

-u: displays all UDP protocol connections

-I: displays the status of the auto-configured port

-l: only displays the status of the service network with a connection status of listening

-p: display pid/program name

Several states of TCP connection

ESTABLISHED has been established

CLOSED is closed

LISTENING is listening.

FIN-WAIT-2 waits for the connection to close

TIME-WAIT waits long enough to ensure that the server closes the connection properly

Thank you for reading! On how to view the port of linux to share here, I hope the above content can be of some help to you, so that you can learn more knowledge. If you think the article is good, you can share it and let more people see it.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.