Arantia 2010 S.L.

Any device whose MAC address begins with A4:B1:21 has a network interface built by Arantia 2010 S.L.. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

A4:B1:21

Organization

Arantia 2010 S.L.

Address

Volta do Castro s/n Santiago de Compostela A Coruña ES 15706

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.