Internet Laboratories, Inc.

Any device whose MAC address begins with B4:1D:EF has a network interface built by Internet Laboratories, Inc.. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

B4:1D:EF

Organization

Internet Laboratories, Inc.

Address

P.O. Box 7697 Atlanta GA US 30357

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.