Open Networking Laboratory

Any device whose MAC address begins with A4:23:05 has a network interface built by Open Networking Laboratory. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

A4:23:05

Organization

Open Networking Laboratory

Address

1000 El Camino Real Menlo Park CA US 94025

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.