Hitachi High-Tech Control Systems Corporation

Any device whose MAC address begins with 00:21:BF has a network interface built by Hitachi High-Tech Control Systems Corporation. 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:BF

Organization

Hitachi High-Tech Control Systems Corporation

Address

500,Miyu-cho Mito-shi Ibaraki-ken JP 319-0316

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.