How to Identify Devices on a Network – IT Glossary | SolarWinds

How to manually identify unknown devices on a network

A simple way to identify an “unknown device on a network” is through the command-line interface (CLI) of your computer system. Operating systems such as Windows, Linux, and macOS have their own set of networking commands such as “ipconfig” and “ping” for basic scanning and troubleshooting. Mapping network devices also requires an understanding of IP address allocation. To communicate with other nodes or machines in a network, a device requires a unique IP address. The address is either dynamically assigned by a DHCP server or static and manually.

Outlined below are steps to help you identify network devices, including unknown equipment:

• Open the Command prompt or Terminal in your Windows, Linux, or macOS system.
• Search all the network settings, such as default gateway and IP address, through the command prompt.
• For Windows: Type “ipconfig” and hit enter. It will display the subnet mask, the default gateway, and the IPv4 address of your computer.
• For Linux and macOS: Enter the “ifconfig” command to view all the network settings.
• Type the command “arp -a” to view the list of all IP addresses connected to your network. This will also display the MAC address and the allocation type (static and dynamic) of all your network devices.
• Type “nslookup” followed by any IP address obtained through the “arp” command in the previous step. This will show the hostname of entered IP address or any unknown device on network.