Matuschek Messtechnik GmbH

Any device whose MAC address begins with 00:21:78 has a network interface built by Matuschek Messtechnik GmbH. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

00:21:78

Organization

Matuschek Messtechnik GmbH

Address

Werner Heisenberg Straße 14 Alsdorf NRW DE 52477

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.