Which company owns MAC address prefix A4:56:1B?

MAC address prefix A4:56:1B is registered to MCOT Corporation in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with A4:56:1B has a network interface built by MCOT Corporation.

What is the OUI A4:56:1B?

A4:56:1B is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to MCOT Corporation. It covers every address from A4:56:1B:00:00:00 to A4:56:1B:FF:FF:FF, or 16,777,216 addresses in total. It is also written A4-56-1B.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in A4:56:1B:00:00:00 that is A4:56:1B — 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 MCOT Corporation located?

MCOT Corporation is listed at Yogohigashi 1-5-12 Matsuyama city Ehime prefecture JP 790-0044 in the IEEE OUI registry entry for A4:56:1B. This is the address the organization registered with the IEEE, which may differ from its current operating address.

MCOT Corporation

MAC address prefix A4:56:1B is registered to MCOT Corporation in the IEEE OUI registry. Any device whose MAC address begins with A4:56:1B has a network interface built by MCOT Corporation. 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 A4:56:1B:00:00:00 to A4:56:1B:FF:FF:FF.

OUI prefix: A4:56:1B
Hyphen form: A4-56-1B
MAC range: A4:56:1B:00:00:00 – A4:56:1B:FF:FF:FF
Addresses in block: 16,777,216
Organization: MCOT Corporation
Address: Yogohigashi 1-5-12 Matsuyama city Ehime prefecture JP 790-0044
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 "MCOT Corporation"
archived source →
2026-07-17Assigned to "MCOT Corporation"

Nearby in the registry

The prefixes assigned immediately before and after A4:56:1B:

FAQ

Which company owns MAC address prefix A4:56:1B?: MAC address prefix A4:56:1B is registered to MCOT Corporation in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with A4:56:1B has a network interface built by MCOT Corporation.
What is the OUI A4:56:1B?: A4:56:1B is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to MCOT Corporation. It covers every address from A4:56:1B:00:00:00 to A4:56:1B:FF:FF:FF, or 16,777,216 addresses in total. It is also written A4-56-1B.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in A4:56:1B:00:00:00 that is A4:56:1B — 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 MCOT Corporation located?: MCOT Corporation is listed at Yogohigashi 1-5-12 Matsuyama city Ehime prefecture JP 790-0044 in the IEEE OUI registry entry for A4:56:1B. This is the address the organization registered with the IEEE, which may differ from its current operating address.