Introduction

The nc command, also known as Netcat, is a command-line networking tool that has been around for many years. It is a simple yet powerful tool that can be used for a wide range of tasks such as network communication, port scanning, file transfer, and network testing.

The nc command is available on most Linux distributions and can be installed using the default package manager.

In this blog post, we'll explore how to use the nc command in Linux and provide practical examples to help you get started.

Using the nc Command

For Network Communication

The nc command can be used for network communication between two networked devices. This can be useful in situations where you need to transfer data between devices or when you need to check whether a specific port is open or closed.

To establish a connection between two devices using the nc command, you need to run the following command on the device that will act as the server:

nc -l <port_number>

This command will listen for incoming connections on the specified port number.

To connect to this device from another device, you need to run the following command:

nc <server_ip_address> <port_number>

This command will establish a connection to the server on the specified port number.

Once the connection is established, you can transfer data between the two devices.

For Port Scanning

The nc command can also be used for port scanning, which is the process of checking whether a specific port is open or closed.

To perform a port scan using the nc command, you need to run the following command:

nc -z <server_ip_address> <port_range>

In the above command, port_range specifies the range of ports you want to scan. The -z option tells the nc command to scan for open ports without sending any data.

Once the command is executed, the nc command will display a list of open ports on the specified device.

For File Transfer

The nc command can also be used for file transfer between two devices.

To transfer a file using the nc command, you need to run the following command on the device that will act as the server:

nc -l <port_number> > <file_name>

This command will listen for incoming connections on the specified port number and save the incoming data to the specified file name.

To send a file to the server from another device, you need to run the following command:

nc <server_ip_address> <port_number> < <file_name>

This command will establish a connection to the server on the specified port number and send the data from the specified file to the server.

Conclusion

The nc command, also known as Netcat, is a versatile networking tool that can be used for a variety of tasks such as network communication, port scanning, file transfer, and network testing.

In this blog post, we've explored how to use the nc command in Linux and provided practical examples to help you get started. With this knowledge, you can now use the nc command to perform various network tasks efficiently and effectively.