HDSN

Any device whose MAC address begins with 20:31:EB has a network interface built by HDSN. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

20:31:EB

Organization

HDSN

Address

4 allée des roseaux Saint mitre les remparts BDR FR 13920

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.