Which company owns MAC address prefix BC:D9:40?

MAC address prefix BC:D9:40 is registered to ASR Co,.Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with BC:D9:40 has a network interface built by ASR Co,.Ltd..

What is the OUI BC:D9:40?

BC:D9:40 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to ASR Co,.Ltd.. It covers every address from BC:D9:40:00:00:00 to BC:D9:40:FF:FF:FF, or 16,777,216 addresses in total. It is also written BC-D9-40.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in BC:D9:40:00:00:00 that is BC:D9:40 — 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 ASR Co,.Ltd. located?

ASR Co,.Ltd. is listed at 1-3-1 Sotokanda Chiyoda-ku Tokyo JP 101-0021 in the IEEE OUI registry entry for BC:D9:40. This is the address the organization registered with the IEEE, which may differ from its current operating address.

ASR Co,.Ltd.

MAC address prefix BC:D9:40 is registered to ASR Co,.Ltd. in the IEEE OUI registry. Any device whose MAC address begins with BC:D9:40 has a network interface built by ASR Co,.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 BC:D9:40:00:00:00 to BC:D9:40:FF:FF:FF.

OUI prefix: BC:D9:40
Hyphen form: BC-D9-40
MAC range: BC:D9:40:00:00:00 – BC:D9:40:FF:FF:FF
Addresses in block: 16,777,216
Organization: ASR Co,.Ltd.
Address: 1-3-1 Sotokanda Chiyoda-ku Tokyo JP 101-0021
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 "ASR Co,.Ltd."
archived source →
2026-07-17Assigned to "ASR Co,.Ltd."

Nearby in the registry

The prefixes assigned immediately before and after BC:D9:40:

FAQ

Which company owns MAC address prefix BC:D9:40?: MAC address prefix BC:D9:40 is registered to ASR Co,.Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with BC:D9:40 has a network interface built by ASR Co,.Ltd..
What is the OUI BC:D9:40?: BC:D9:40 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to ASR Co,.Ltd.. It covers every address from BC:D9:40:00:00:00 to BC:D9:40:FF:FF:FF, or 16,777,216 addresses in total. It is also written BC-D9-40.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in BC:D9:40:00:00:00 that is BC:D9:40 — 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 ASR Co,.Ltd. located?: ASR Co,.Ltd. is listed at 1-3-1 Sotokanda Chiyoda-ku Tokyo JP 101-0021 in the IEEE OUI registry entry for BC:D9:40. This is the address the organization registered with the IEEE, which may differ from its current operating address.