Which company owns MAC address prefix AC:20:AA?

MAC address prefix AC:20:AA is registered to DMATEK Co., Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with AC:20:AA has a network interface built by DMATEK Co., Ltd..

What is the OUI AC:20:AA?

AC:20:AA is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to DMATEK Co., Ltd.. It covers every address from AC:20:AA:00:00:00 to AC:20:AA:FF:FF:FF, or 16,777,216 addresses in total. It is also written AC-20-AA.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in AC:20:AA:00:00:00 that is AC:20:AA — 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 DMATEK Co., Ltd. located?

DMATEK Co., Ltd. is listed at 11F.-2, No.386, Shizheng Rd., Xitun Dist., Taichung TW 40757 in the IEEE OUI registry entry for AC:20:AA. This is the address the organization registered with the IEEE, which may differ from its current operating address.

DMATEK Co., Ltd.

MAC address prefix AC:20:AA is registered to DMATEK Co., Ltd. in the IEEE OUI registry. Any device whose MAC address begins with AC:20:AA has a network interface built by DMATEK 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 AC:20:AA:00:00:00 to AC:20:AA:FF:FF:FF.

OUI prefix: AC:20:AA
Hyphen form: AC-20-AA
MAC range: AC:20:AA:00:00:00 – AC:20:AA:FF:FF:FF
Addresses in block: 16,777,216
Organization: DMATEK Co., Ltd.
Address: 11F.-2, No.386, Shizheng Rd., Xitun Dist., Taichung TW 40757
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 "DMATEK Co., Ltd."
archived source →
2026-07-17Assigned to "DMATEK Co., Ltd."

Nearby in the registry

The prefixes assigned immediately before and after AC:20:AA:

FAQ

Which company owns MAC address prefix AC:20:AA?: MAC address prefix AC:20:AA is registered to DMATEK Co., Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with AC:20:AA has a network interface built by DMATEK Co., Ltd..
What is the OUI AC:20:AA?: AC:20:AA is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to DMATEK Co., Ltd.. It covers every address from AC:20:AA:00:00:00 to AC:20:AA:FF:FF:FF, or 16,777,216 addresses in total. It is also written AC-20-AA.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in AC:20:AA:00:00:00 that is AC:20:AA — 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 DMATEK Co., Ltd. located?: DMATEK Co., Ltd. is listed at 11F.-2, No.386, Shizheng Rd., Xitun Dist., Taichung TW 40757 in the IEEE OUI registry entry for AC:20:AA. This is the address the organization registered with the IEEE, which may differ from its current operating address.