How to check if port 1433 is open in Linux

View method: 1. Use the lsof command. This command is used to list all files that have been opened in the system. When the command parameter is set to "-i", you can list the processes that meet the conditions. Syntax It is "lsof -i:1433"; 2. Use the "netstat-aptn" command, which can directly view all opened port numbers and directly check whether the result contains port 1433.

#The operating environment of this tutorial: linux7.3 system, Dell G3 computer.

How to check whether port 1433 is open in Linux

The lsof command is used to check the files opened by your process, the process that opened the file, and the ports opened by the process (TCP, UDP). Retrieve/recover deleted files. It is a very convenient system monitoring tool. Because the lsof command needs to access core memory and various files, it needs to be executed by the root user.

In the Linux environment, everything exists in the form of files. Through files, you can not only access regular data, but also network connections and hardware. Therefore, for example, Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) sockets, the system allocates a file descriptor to the application in the background. Regardless of the nature of the file, the file descriptor is used by the application. Provides a common interface for interaction with the underlying operating system. Because the descriptor list of files opened by an application provides a lot of information about the application itself, being able to view this list through the lsof tool can be helpful for system monitoring and troubleshooting.

Syntax:

lsof(选项)

Options:

-a List the processes that open the file;

-c List the specified process The opened file;

-g lists the process details of the GID number;

-d lists the processes occupying the file number;

d List the files opened in the directory;

D Recursively list the files opened in the directory;

-n List the files using NFS File;

-i List processes that meet the criteria. (4, 6, protocol, :port, @ip)

The first method:

Use the lsof command

lsof -i:1433

th Two methods:

Use the netstat-aptn command.

Examples are as follows:

Recommended learning: Linux video tutorial

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