EFFICIENT NETWORKS, INC.

Any device whose MAC address begins with 00:20:EA has a network interface built by EFFICIENT NETWORKS, INC.. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

00:20:EA

Organization

EFFICIENT NETWORKS, INC.

Address

4201 SPRING VALLEY ROAD DALLAS TX US 75244-3666

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.