CORNELL Communications, Inc.

Any device whose MAC address begins with 00:21:C3 has a network interface built by CORNELL Communications, 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

00:21:C3

Organization

CORNELL Communications, Inc.

Address

7915 N. 81st Street Milwaukee Wisconsin US 53223

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.