MAC Address Lookup

What is an OUI?

An OUI (Organizationally Unique Identifier) is the first three octets of a MAC address. The IEEE Registration Authority assigns OUI blocks to hardware manufacturers, meaning the first half of any MAC address tells you exactly who made the network chip. For example, 3C:06:30 is registered to Apple, Inc.

When you spoof your MAC address using MacSpoof, you can choose an Apple OUI so your device looks like an Apple Mac to any router, captive portal, or network scanner — even if you're spoofing for privacy or to bypass time limits.

What the bits tell you

Two bits inside the first octet carry special meaning:

Bit 0 (LSB) — Multicast bit: If set to 1, the address is a multicast/broadcast address. Normal devices use 0 (unicast).

Bit 1 — Locally Administered bit: If set to 1, the address was manually assigned (software-spoofed). If 0, it was burned into the hardware at the factory. MacSpoof sets this bit in Random mode to be transparent about spoofing.