Which company owns MAC address prefix EC:21:25?

MAC address prefix EC:21:25 is registered to Toshiba Corp. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with EC:21:25 has a network interface built by Toshiba Corp..

What is the OUI EC:21:25?

EC:21:25 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Toshiba Corp.. It covers every address from EC:21:25:00:00:00 to EC:21:25:FF:FF:FF, or 16,777,216 addresses in total. It is also written EC-21-25.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in EC:21:25:00:00:00 that is EC:21:25 — 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 Toshiba Corp. located?

Toshiba Corp. is listed at 1-1 Shibaura 1-Chome, Minato-Ku Tokyo JP 105-8001 in the IEEE OUI registry entry for EC:21:25. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does Toshiba Corp. own?

Toshiba Corp. holds 3 OUI prefixes in the IEEE registry, of which EC:21:25 is one. A device made by Toshiba Corp. could carry a MAC address from any of them.

Toshiba Corp.

MAC address prefix EC:21:25 is registered to Toshiba Corp. in the IEEE OUI registry. Any device whose MAC address begins with EC:21:25 has a network interface built by Toshiba Corp.. 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 EC:21:25:00:00:00 to EC:21:25:FF:FF:FF.

OUI prefix: EC:21:25
Hyphen form: EC-21-25
MAC range: EC:21:25:00:00:00 – EC:21:25:FF:FF:FF
Addresses in block: 16,777,216
Organization: Toshiba Corp.
Address: 1-1 Shibaura 1-Chome, Minato-Ku Tokyo JP 105-8001
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.

Other prefixes from Toshiba Corp.

Toshiba Corp. holds 3 OUI prefixes in total. A device with this exact prefix could just as well carry any of these:

Assignment history (2)

The IEEE registry publishes current state only — this is the change record we've kept since we started tracking it daily.

2022-07-11Assigned to "Toshiba Corp."
archived source →
2026-07-17Assigned to "Toshiba Corp."

Nearby in the registry

The prefixes assigned immediately before and after EC:21:25:

FAQ

Which company owns MAC address prefix EC:21:25?: MAC address prefix EC:21:25 is registered to Toshiba Corp. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with EC:21:25 has a network interface built by Toshiba Corp..
What is the OUI EC:21:25?: EC:21:25 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Toshiba Corp.. It covers every address from EC:21:25:00:00:00 to EC:21:25:FF:FF:FF, or 16,777,216 addresses in total. It is also written EC-21-25.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in EC:21:25:00:00:00 that is EC:21:25 — 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 Toshiba Corp. located?: Toshiba Corp. is listed at 1-1 Shibaura 1-Chome, Minato-Ku Tokyo JP 105-8001 in the IEEE OUI registry entry for EC:21:25. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does Toshiba Corp. own?: Toshiba Corp. holds 3 OUI prefixes in the IEEE registry, of which EC:21:25 is one. A device made by Toshiba Corp. could carry a MAC address from any of them.