Which company owns MAC address prefix 04:19:7F?

MAC address prefix 04:19:7F is registered to Grasphere Japan in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 04:19:7F has a network interface built by Grasphere Japan.

What is the OUI 04:19:7F?

04:19:7F is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Grasphere Japan. It covers every address from 04:19:7F:00:00:00 to 04:19:7F:FF:FF:FF, or 16,777,216 addresses in total. It is also written 04-19-7F.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 04:19:7F:00:00:00 that is 04:19:7F — 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 Grasphere Japan located?

Grasphere Japan is listed at 3-1-11 NNT build. Tokyo JP 1030013 in the IEEE OUI registry entry for 04:19:7F. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Grasphere Japan

MAC address prefix 04:19:7F is registered to Grasphere Japan in the IEEE OUI registry. Any device whose MAC address begins with 04:19:7F has a network interface built by Grasphere Japan. 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 04:19:7F:00:00:00 to 04:19:7F:FF:FF:FF.

OUI prefix: 04:19:7F
Hyphen form: 04-19-7F
MAC range: 04:19:7F:00:00:00 – 04:19:7F:FF:FF:FF
Addresses in block: 16,777,216
Organization: Grasphere Japan
Address: 3-1-11 NNT build. Tokyo JP 1030013
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.

2018-12-21Assigned to "Grasphere Japan"
archived source →
2026-07-17Assigned to "Grasphere Japan"

Nearby in the registry

The prefixes assigned immediately before and after 04:19:7F:

FAQ

Which company owns MAC address prefix 04:19:7F?: MAC address prefix 04:19:7F is registered to Grasphere Japan in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 04:19:7F has a network interface built by Grasphere Japan.
What is the OUI 04:19:7F?: 04:19:7F is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Grasphere Japan. It covers every address from 04:19:7F:00:00:00 to 04:19:7F:FF:FF:FF, or 16,777,216 addresses in total. It is also written 04-19-7F.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 04:19:7F:00:00:00 that is 04:19:7F — 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 Grasphere Japan located?: Grasphere Japan is listed at 3-1-11 NNT build. Tokyo JP 1030013 in the IEEE OUI registry entry for 04:19:7F. This is the address the organization registered with the IEEE, which may differ from its current operating address.