Which company owns MAC address prefix D0:A4:B1?

MAC address prefix D0:A4:B1 is registered to Sonifex Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with D0:A4:B1 has a network interface built by Sonifex Ltd..

What is the OUI D0:A4:B1?

D0:A4:B1 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Sonifex Ltd.. It covers every address from D0:A4:B1:00:00:00 to D0:A4:B1:FF:FF:FF, or 16,777,216 addresses in total. It is also written D0-A4-B1.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in D0:A4:B1:00:00:00 that is D0:A4:B1 — and look that prefix up in the IEEE OUI registry. If the second-lowest bit of the first octet is set, the address is locally administered (a randomized or private MAC), which belongs to no manufacturer and will not resolve; modern phones and laptops use these by default on each network.

Where is Sonifex Ltd. located?

Sonifex Ltd. is listed at 61 Station Road Irthlingborough Northamptonshire GB NN9 5QE in the IEEE OUI registry entry for D0:A4:B1. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Sonifex Ltd.

MAC address prefix D0:A4:B1 is registered to Sonifex Ltd. in the IEEE OUI registry. Any device whose MAC address begins with D0:A4:B1 has a network interface built by Sonifex Ltd.. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address — it covers every MAC from D0:A4:B1:00:00:00 to D0:A4:B1:FF:FF:FF.

OUI prefix: D0:A4:B1
Hyphen form: D0-A4-B1
MAC range: D0:A4:B1:00:00:00 – D0:A4:B1:FF:FF:FF
Addresses in block: 16,777,216
Organization: Sonifex Ltd.
Address: 61 Station Road Irthlingborough Northamptonshire GB NN9 5QE
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.

Assignment history (2)

The IEEE registry publishes current state only — this is the change record we've kept since we started tracking it daily.

2016-07-29Assigned to "Sonifex Ltd."
archived source →
2026-07-17Assigned to "Sonifex Ltd."

Nearby in the registry

The prefixes assigned immediately before and after D0:A4:B1:

FAQ

Which company owns MAC address prefix D0:A4:B1?: MAC address prefix D0:A4:B1 is registered to Sonifex Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with D0:A4:B1 has a network interface built by Sonifex Ltd..
What is the OUI D0:A4:B1?: D0:A4:B1 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Sonifex Ltd.. It covers every address from D0:A4:B1:00:00:00 to D0:A4:B1:FF:FF:FF, or 16,777,216 addresses in total. It is also written D0-A4-B1.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in D0:A4:B1:00:00:00 that is D0:A4:B1 — and look that prefix up in the IEEE OUI registry. If the second-lowest bit of the first octet is set, the address is locally administered (a randomized or private MAC), which belongs to no manufacturer and will not resolve; modern phones and laptops use these by default on each network.
Where is Sonifex Ltd. located?: Sonifex Ltd. is listed at 61 Station Road Irthlingborough Northamptonshire GB NN9 5QE in the IEEE OUI registry entry for D0:A4:B1. This is the address the organization registered with the IEEE, which may differ from its current operating address.