Which company owns MAC address prefix 00:00:BD?

MAC address prefix 00:00:BD is registered to RYOSEI, Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:00:BD has a network interface built by RYOSEI, Ltd..

What is the OUI 00:00:BD?

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

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 00:00:BD:00:00:00 that is 00:00:BD — 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 RYOSEI, Ltd. located?

RYOSEI, Ltd. is listed at 16-4, kitahatsushima-cho Amagasaki-shi Hyogo JP 660-0834 in the IEEE OUI registry entry for 00:00:BD. This is the address the organization registered with the IEEE, which may differ from its current operating address.

RYOSEI, Ltd.

MAC address prefix 00:00:BD is registered to RYOSEI, Ltd. in the IEEE OUI registry. Any device whose MAC address begins with 00:00:BD has a network interface built by RYOSEI, 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 00:00:BD:00:00:00 to 00:00:BD:FF:FF:FF.

OUI prefix: 00:00:BD
Hyphen form: 00-00-BD
MAC range: 00:00:BD:00:00:00 – 00:00:BD:FF:FF:FF
Addresses in block: 16,777,216
Organization: RYOSEI, Ltd.
Address: 16-4, kitahatsushima-cho Amagasaki-shi Hyogo JP 660-0834
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 (4)

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 "MITSUBISHI CABLE COMPANY"
archived source →
2018-12-21Renamed from "MITSUBISHI CABLE COMPANY" to "Mitsubishi Cable Industries, Ltd. / Ryosei Systems"
archived source →
2022-07-11Renamed from "Mitsubishi Cable Industries, Ltd. / Ryosei Systems" to "RYOSEI, Ltd."
archived source →
2026-07-17Assigned to "RYOSEI, Ltd."

Nearby in the registry

The prefixes assigned immediately before and after 00:00:BD:

FAQ

Which company owns MAC address prefix 00:00:BD?: MAC address prefix 00:00:BD is registered to RYOSEI, Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:00:BD has a network interface built by RYOSEI, Ltd..
What is the OUI 00:00:BD?: 00:00:BD is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to RYOSEI, Ltd.. It covers every address from 00:00:BD:00:00:00 to 00:00:BD:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-00-BD.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 00:00:BD:00:00:00 that is 00:00:BD — 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 RYOSEI, Ltd. located?: RYOSEI, Ltd. is listed at 16-4, kitahatsushima-cho Amagasaki-shi Hyogo JP 660-0834 in the IEEE OUI registry entry for 00:00:BD. This is the address the organization registered with the IEEE, which may differ from its current operating address.