OT Systems Limited

Any device whose MAC address begins with 80:34:57 has a network interface built by OT Systems Limited. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

80:34:57

Organization

OT Systems Limited

Address

Unit 1023, 10/F., Landmark North, Sheung Shui, N. T. HK

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.