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Utility #8IEEE Registry
MAC Address / OUI Vendor Lookup
Identify the hardware manufacturer of any network device, analyze bitwise IEEE unicast/multicast flags, and normalize notation formats instantly.
Try sample MACs:
Anatomy of a 48-Bit Ethernet MAC Address
Every Ethernet frame carries a 6-byte source and destination physical address divided into manufacturer identification and device serialization.
1. First 24 Bits: OUI
The Organizationally Unique Identifier (OUI) is purchased from IEEE by manufacturers to brand hardware interface cards globally.
2. Last 24 Bits: NIC Specific
The lower 3 bytes are allocated sequentially by the vendor to create unique serialized hardware chips.
3. Individual vs. Group Bit
Bit 0 distinguishes between point-to-point unicast transmissions and broadcast/multicast group flooding across switches.
Frequently Asked Questions About MAC Addresses
Technical answers regarding vendor registers, Wi-Fi randomization, and framing.
A MAC (Media Access Control) address is a unique 48-bit hardware identifier assigned to a network interface controller (NIC). The first 24 bits (3 octets) represent the OUI (Organizationally Unique Identifier) assigned by the IEEE to manufacturers like Apple, Cisco, Intel, or Samsung.
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