Software Freedom Conservancy

Any device whose MAC address begins with 28:17:CB has a network interface built by Software Freedom Conservancy. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

28:17:CB

Organization

Software Freedom Conservancy

Address

137 MONTAGUE ST STE 380 Brooklyn NY US 11201

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.