CABLE AND WIRELESS

Any device whose MAC address begins with 00:40:74 has a network interface built by CABLE AND WIRELESS. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

00:40:74

Organization

CABLE AND WIRELESS

Address

COMMUNICATIONS, INC. VIENNA VA US 22182-3964

Source

IEEE OUI registry

Have a full MAC address? Look it up— we'll also tell you if it's a randomized (private) address rather than a real manufacturer prefix.