check if port 80 is open and whcih process is runing and pid linux

Introduction

One of the fundamental steps in ensuring the security and smooth functioning of a Linux system is to check if port 80 is open and which process is running on it. Port 80, also commonly known as the HTTP port, is essential for web servers to communicate with clients. In this article, we will outline the simple steps to check the status of port 80 and identify the running process and its corresponding process ID (PID).

Checking Port 80

To determine if port 80 is open on your Linux system, you can use the netstat command. Open your terminal and enter the following command:

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sudo netstat -tlnp

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The -tlnp flag allows us to display the listening (‘l’) TCP (-t) network connections, along with their respective addresses and port numbers. The ‘n’ option ensures that the output is shown in numerical form, making it easier to identify specific ports.

Identifying the Process

Once you have executed the above command, you will get a list of all active network connections. Look for the entry corresponding to port 80. In the last column of this entry, you will find the Process ID (PID) associated with the running process. This PID helps in identifying which process is using port 80.

To get more details about the process, use the following command:

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sudo lsof -i :80

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This command specifically looks for processes using port 80. The output will provide information such as the process name, PID, user, and the associated files or network sockets.

Conclusion

Checking if port 80 is open and which process is running on it is crucial for maintaining the security and functionality of a Linux system. By using the netstat and lsof commands, we can easily determine if port 80 is open and identify the process and its PID. Regularly monitoring and managing your system’s open ports, particularly port 80, is an essential security practice.