MAC Address Lookup
Identify the manufacturer of any network device from its MAC address. Supports OUI lookup for switches, routers, wireless APs and more.
About MAC Address Lookup
A MAC (Media Access Control) address is a unique identifier assigned to a network interface card (NIC) at the hardware level. It is a 48-bit (6-byte) address typically written as six pairs of hexadecimal digits separated by colons or hyphens (e.g. 00:1A:2B:3C:4D:5E). MAC addresses operate at Layer 2 of the OSI model and are used for communication within a local network segment.
OUI: the vendor prefix
The first three bytes (24 bits) of a MAC address form the OUI (Organizationally Unique Identifier) — a prefix assigned by the IEEE to each manufacturer. This lookup identifies the manufacturer from the OUI. For example, MAC addresses starting with 3C:22:FB are Apple devices, while 00:50:56 identifies VMware virtual machines.
MAC address types
- Globally administered (UAA) — Assigned by the manufacturer. The second-least-significant bit of the first byte is 0. This is the standard type for physical hardware NICs.
- Locally administered (LAA) — The second-least-significant bit of the first byte is 1. These are manually set or software-generated addresses, common in virtual machines and containers.
- Unicast — The least-significant bit of the first byte is 0. Addresses a single device.
- Multicast — The least-significant bit of the first byte is 1. Addresses a group of devices. The special broadcast address
FF:FF:FF:FF:FF:FFreaches all devices on the segment.
MAC address randomisation
Modern operating systems (iOS 14+, Android 10+, Windows 10+) randomise MAC addresses for Wi-Fi scanning and connections to prevent tracking. The randomised address has the locally administered bit set, so the OUI lookup will not identify a real manufacturer.