Beijing GuangXin Technology Co., Ltd

Any device whose MAC address begins with B4:21:1D has a network interface built by Beijing GuangXin Technology Co., Ltd. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

B4:21:1D

Organization

Beijing GuangXin Technology Co., Ltd

Address

Room 313,B Bld,Horizon International Tower,Zhichun Road,6,Haidian District,Beijing City,P.R.China Beijing CN 100086

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.