BeNeXt B.V.

Any device whose MAC address begins with F4:03:21 has a network interface built by BeNeXt B.V.. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

F4:03:21

Organization

BeNeXt B.V.

Address

Ter Gouwstraat 3 Amsterdam NH NL 1093JX

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.