Siemens AG I IA PP PRM

Any device whose MAC address begins with 78:9F:87 has a network interface built by Siemens AG I IA PP PRM. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

78:9F:87

Organization

Siemens AG I IA PP PRM

Address

Gleiwitzer Strasse 555 Nuremberg Bavaria DE 90475

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.