Which company owns MAC address prefix D8:09:4E?

MAC address prefix D8:09:4E is registered to Active Brains in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with D8:09:4E has a network interface built by Active Brains.

What is the OUI D8:09:4E?

D8:09:4E is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Active Brains. It covers every address from D8:09:4E:00:00:00 to D8:09:4E:FF:FF:FF, or 16,777,216 addresses in total. It is also written D8-09-4E.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in D8:09:4E:00:00:00 that is D8:09:4E — 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 Active Brains located?

Active Brains is listed at Yokohama Mitsui Bldg.12F, 1-1-2 Takashima, Nishi-ku Yokohama Kanagawa JP 220-0011 in the IEEE OUI registry entry for D8:09:4E. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Active Brains

MAC address prefix D8:09:4E is registered to Active Brains in the IEEE OUI registry. Any device whose MAC address begins with D8:09:4E has a network interface built by Active Brains. 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 D8:09:4E:00:00:00 to D8:09:4E:FF:FF:FF.

OUI prefix: D8:09:4E
Hyphen form: D8-09-4E
MAC range: D8:09:4E:00:00:00 – D8:09:4E:FF:FF:FF
Addresses in block: 16,777,216
Organization: Active Brains
Address: Yokohama Mitsui Bldg.12F, 1-1-2 Takashima, Nishi-ku Yokohama Kanagawa JP 220-0011
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.

2023-07-11Assigned to "Active Brains"
archived source →
2026-07-17Assigned to "Active Brains"

Nearby in the registry

The prefixes assigned immediately before and after D8:09:4E:

FAQ

Which company owns MAC address prefix D8:09:4E?: MAC address prefix D8:09:4E is registered to Active Brains in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with D8:09:4E has a network interface built by Active Brains.
What is the OUI D8:09:4E?: D8:09:4E is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Active Brains. It covers every address from D8:09:4E:00:00:00 to D8:09:4E:FF:FF:FF, or 16,777,216 addresses in total. It is also written D8-09-4E.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in D8:09:4E:00:00:00 that is D8:09:4E — 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 Active Brains located?: Active Brains is listed at Yokohama Mitsui Bldg.12F, 1-1-2 Takashima, Nishi-ku Yokohama Kanagawa JP 220-0011 in the IEEE OUI registry entry for D8:09:4E. This is the address the organization registered with the IEEE, which may differ from its current operating address.