Which company owns MAC address prefix B4:DF:09?

MAC address prefix B4:DF:09 is registered to FLUX:: in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with B4:DF:09 has a network interface built by FLUX::.

What is the OUI B4:DF:09?

B4:DF:09 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to FLUX::. It covers every address from B4:DF:09:00:00:00 to B4:DF:09:FF:FF:FF, or 16,777,216 addresses in total. It is also written B4-DF-09.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in B4:DF:09:00:00:00 that is B4:DF:09 — 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 FLUX:: located?

FLUX:: is listed at 8500 Balboa Boulevard Northridge CA US 91325 in the IEEE OUI registry entry for B4:DF:09. This is the address the organization registered with the IEEE, which may differ from its current operating address.

FLUX::

MAC address prefix B4:DF:09 is registered to FLUX:: in the IEEE OUI registry. Any device whose MAC address begins with B4:DF:09 has a network interface built by FLUX::. 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 B4:DF:09:00:00:00 to B4:DF:09:FF:FF:FF.

OUI prefix: B4:DF:09
Hyphen form: B4-DF-09
MAC range: B4:DF:09:00:00:00 – B4:DF:09:FF:FF:FF
Addresses in block: 16,777,216
Organization: FLUX::
Address: 8500 Balboa Boulevard Northridge CA US 91325
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.

2026-06-20Assigned to "FLUX::"
archived source →
2026-07-17Assigned to "FLUX::"

Nearby in the registry

The prefixes assigned immediately before and after B4:DF:09:

FAQ

Which company owns MAC address prefix B4:DF:09?: MAC address prefix B4:DF:09 is registered to FLUX:: in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with B4:DF:09 has a network interface built by FLUX::.
What is the OUI B4:DF:09?: B4:DF:09 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to FLUX::. It covers every address from B4:DF:09:00:00:00 to B4:DF:09:FF:FF:FF, or 16,777,216 addresses in total. It is also written B4-DF-09.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in B4:DF:09:00:00:00 that is B4:DF:09 — 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 FLUX:: located?: FLUX:: is listed at 8500 Balboa Boulevard Northridge CA US 91325 in the IEEE OUI registry entry for B4:DF:09. This is the address the organization registered with the IEEE, which may differ from its current operating address.