Cogent Defence & Security Networks,

Any device whose MAC address begins with 00:0C:3F has a network interface built by Cogent Defence & Security Networks,. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

00:0C:3F

Organization

Cogent Defence & Security Networks,

Address

Meadows Road, Newport, South Wales, GB NP19 4SS

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.