MAC Address Lookup

How MAC address lookup works

The first three byte pairs of a MAC address (called the OUI, or Organizationally Unique Identifier) are assigned to a specific manufacturer by the IEEE. This tool checks that prefix against a public registry to identify which company made the network device.

The remaining bytes are assigned by the manufacturer to uniquely identify individual devices, so they don't reveal anything further about the device itself.

Common uses

This is useful for network administrators identifying unknown devices on a network, troubleshooting connectivity issues, or verifying that a device matches its claimed manufacturer. Note that MAC addresses can be manually changed ("spoofed") on many devices, so a lookup reflects the registered vendor for that address prefix, not necessarily a guarantee about the physical device.