Siemens AG Energy Management Division

Any device whose MAC address begins with B4:B1:5A has a network interface built by Siemens AG Energy Management Division. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

B4:B1:5A

Organization

Siemens AG Energy Management Division

Address

Humboldtstr. 59 Nurnberg Bavaria DE 90459

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.