SK Networks Service CO., LTD.

Any device whose MAC address begins with 40:D4:BD has a network interface built by SK Networks Service CO., LTD.. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

40:D4:BD

Organization

SK Networks Service CO., LTD.

Address

120, Jangan-ro, Jangan-gu Suwon-si Gyeonggi-do KR 16312

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.