Knowing who is connected to your network can sometimes be helpful. For example, you may need to check the status of certain devices (whether they are up or down), find additional static IP addresses, or list devices. In addition, this information can also help you identify any unauthorized access to your network and shared resources.
While you can check the connected IP from your router’s configuration page, it does not show static IP addresses. Fortunately, there are several other methods that let you find all IP addresses on a network. Let’s explore some of them.
Finding IP Addresses on a Network Using ARP
arp is a built-in command line utility used to view and modify the system’s ARP cache. It is also used to find the MAC address of a system for a given IP address because the ARP cache stores the IP to MAC address mapping for the system it communicates with.
Using the arp command, you can also find all the IP addresses on your network. If arp is not already installed or accidentally removed on your Linux machine, you can install it with the following simple command.
Finding IP addresses on a network using nmap
Nmap is a free and open-source tool used for network scanning and mapping. Using nmap, you can find out who is connected to your network, their IP and MAC addresses, operating system details, and the services they are running. It is a cross-platform tool available for both Linux and Windows.
Using Angry IP Scanner
Angry IP Scanner is an open-source and cross-platform IP address and port scanner that pings every IP address in a defined range to check that it is alive and responding. For each live host, it determines its hostname, MAC address, hardware manufacturer, and open ports.
You can also export the scanned results to CSV, TXT and XML file. Angry IP Scanner is available for Linux, Windows, and macOS.
Installing Angry IP Scanner on Linux
On Linux distributions such as Ubuntu, Debian, and Fedora, you can easily install Angry IP Scanner by downloading its DEB or RPM package, either from the GitHub release page or by using the wget command.
Installing Angry IP Scanner on Windows
To install Angry IP Scanner on Windows, download the installer file from the GitHub release page. Once downloaded, double-click on the installer file to install it.
To find all IP addresses on your network, launch Angry IP Scanner and specify IP ranges (starting and ending IP addresses) or network IDs with prefixes. You can also scan IP addresses from a text file. Then, click on the Start button to start the scanning process.
Once the scanning is complete, it will display all the IP addresses scanned in the defined range. You can also include additional details like MAC Address, MAC Vendor, Port etc. in the results from Tools > Fetchers option.
Listing IP Addresses in a Network Using NetDiscover
Netdiscover is another useful command-line network exploration utility that can discover all active hosts on a network using ARP requests. For all discovered hosts, it displays their IP address, MAC address, and hardware manufacturer.
You can also use the Netdiscover utility to find all IP addresses on your network. However, the NetDiscover tool is only available for Linux.
Discovery of all IP addresses on your network
Knowing all the IP addresses on a network can help you identify potential security risks and troubleshoot connectivity issues. Basic commands like arp and netdiscover can provide a list of connected devices with their IP and MAC addresses, while tools like nmap and Angry IP Scanner can give you more insight into live hosts.