How to Find the Unused IP Addresses on my Network in Linux?

We all know that multiple devices can be connected with each other over a network. These devices have dedicated IP addresses. However, you want to assign an IP address to a device at times, and you want to look for a valid and unused IP address on the network. In today's article, we will discuss some methods of finding the unused IP addresses on the network in Linux Mint 20.

Methods of Finding the Unused IP Addresses on my Network in Linux Mint 20

For finding the unused IP addresses on your network in Linux Mint 20, you can follow any of the two methods stated below:

Method # 1: Using the “nmap” Utility to Find the Unused IP Addresses on my Network in Linux Mint 20

For using the “nmap” utility to find the unused IP addresses on your network in Linux Mint 20, you will have to execute the following steps:

Step # 1: Install the “nmap” Utility on your Linux Mint 20 System

First, you need to install the “nmap” utility on your Linux Mint 20 system with the command shown below:

$ sudo apt-get install nmap

After installing this utility, you can use it to find the unused IP addresses on your network.

Step # 2: Use the “nmap” Utility to Find the Unused IP Addresses on my Network in Linux Mint 20

Now you need to execute the following command in your Linux Mint 20 terminal to find the unused IP addresses on your network with the “nmap” utility:

$ nmap -sn 192.168.1.0/24

The output of this command is shown in the image below:

Method # 2: Using the “arp-scan” Utility to Find the Unused IP Addresses on my Network in Linux Mint 20

For using the “arp-scan” utility to find the unused IP addresses on your network in Linux Mint 20, you will have to execute the following steps:

Step # 1: Install the “arp-scan” Utility on your Linux Mint 20 System

First, you need to install the “arp-scan” utility on your Linux Mint 20 system with the command shown below:

$ sudo apt-get install -y arp-scan

After installing this utility, you can use it to find the unused IP addresses on your network.

Step # 2: Use the “arp-scan” Utility to Find the Unused IP Addresses on my Network in Linux Mint 20

Now you need to execute the following command in your Linux Mint 20 terminal to find the unused IP addresses on your network with the “arp-scan” utility:

$ sudo arp-scan -I NetworkInterfaceName 192.168.1.0/24

Here, you need to replace NetworkInterfaceName with the name of the network interface whose unused IP addresses you want to find out. In our case, we have replaced it with “enp0s3”.

The output of this command is shown in the image below:

Conclusion

By picking either of the two methods shared in this article, you can conveniently find out any unused IP addresses on your network and use them to serve any desired purposes.