W. L. Gore & Associates

Any device whose MAC address begins with 00:21:77 has a network interface built by W. L. Gore & Associates. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

00:21:77

Organization

W. L. Gore & Associates

Address

402 Vieves Way Elkton MD US 21921

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.