Alarm.com

Any device whose MAC address begins with B8:3A:9D has a network interface built by Alarm.com. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

B8:3A:9D

Organization

Alarm.com

Address

8281 Greensboro Dr., Suite 100 Tysons VA US 22102

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.