ZF

Any device whose MAC address begins with 80:56:3C has a network interface built by ZF. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

80:56:3C

Organization

ZF

Address

Ehlersstraße 50 Friedrichshafen BW DE 88046

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.