LEGO System A/S

Any device whose MAC address begins with 90:84:2B has a network interface built by LEGO System A/S. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

90:84:2B

Organization

LEGO System A/S

Address

Aastvej 1 Billund DK DK-7190

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.