Which company owns MAC address prefix A0:99:21?

MAC address prefix A0:99:21 is registered to GD Midea Air-Conditioning Equipment Co.,Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with A0:99:21 has a network interface built by GD Midea Air-Conditioning Equipment Co.,Ltd..

What is the OUI A0:99:21?

A0:99:21 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to GD Midea Air-Conditioning Equipment Co.,Ltd.. It covers every address from A0:99:21:00:00:00 to A0:99:21:FF:FF:FF, or 16,777,216 addresses in total. It is also written A0-99-21.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in A0:99:21:00:00:00 that is A0:99:21 — 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 GD Midea Air-Conditioning Equipment Co.,Ltd. located?

GD Midea Air-Conditioning Equipment Co.,Ltd. is listed at Midea Global Innovation Center,Beijiao Town,Shunde Foshan Guangdong CN 528311 in the IEEE OUI registry entry for A0:99:21. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does GD Midea Air-Conditioning Equipment Co.,Ltd. own?

GD Midea Air-Conditioning Equipment Co.,Ltd. holds 53 OUI prefixes in the IEEE registry, of which A0:99:21 is one. A device made by GD Midea Air-Conditioning Equipment Co.,Ltd. could carry a MAC address from any of them.

GD Midea Air-Conditioning Equipment Co.,Ltd.

MAC address prefix A0:99:21 is registered to GD Midea Air-Conditioning Equipment Co.,Ltd. in the IEEE OUI registry. Any device whose MAC address begins with A0:99:21 has a network interface built by GD Midea Air-Conditioning Equipment 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 A0:99:21:00:00:00 to A0:99:21:FF:FF:FF.

OUI prefix: A0:99:21
Hyphen form: A0-99-21
MAC range: A0:99:21:00:00:00 – A0:99:21:FF:FF:FF
Addresses in block: 16,777,216
Organization: GD Midea Air-Conditioning Equipment Co.,Ltd.
Address: Midea Global Innovation Center,Beijiao Town,Shunde Foshan Guangdong CN 528311
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 GD Midea Air-Conditioning Equipment Co.,Ltd.

GD Midea Air-Conditioning Equipment Co.,Ltd. holds 53 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.

2025-05-13Assigned to "GD Midea Air-Conditioning Equipment Co.,Ltd."
archived source →
2026-07-17Assigned to "GD Midea Air-Conditioning Equipment Co.,Ltd."

Nearby in the registry

The prefixes assigned immediately before and after A0:99:21:

FAQ

Which company owns MAC address prefix A0:99:21?: MAC address prefix A0:99:21 is registered to GD Midea Air-Conditioning Equipment Co.,Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with A0:99:21 has a network interface built by GD Midea Air-Conditioning Equipment Co.,Ltd..
What is the OUI A0:99:21?: A0:99:21 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to GD Midea Air-Conditioning Equipment Co.,Ltd.. It covers every address from A0:99:21:00:00:00 to A0:99:21:FF:FF:FF, or 16,777,216 addresses in total. It is also written A0-99-21.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in A0:99:21:00:00:00 that is A0:99:21 — 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 GD Midea Air-Conditioning Equipment Co.,Ltd. located?: GD Midea Air-Conditioning Equipment Co.,Ltd. is listed at Midea Global Innovation Center,Beijiao Town,Shunde Foshan Guangdong CN 528311 in the IEEE OUI registry entry for A0:99:21. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does GD Midea Air-Conditioning Equipment Co.,Ltd. own?: GD Midea Air-Conditioning Equipment Co.,Ltd. holds 53 OUI prefixes in the IEEE registry, of which A0:99:21 is one. A device made by GD Midea Air-Conditioning Equipment Co.,Ltd. could carry a MAC address from any of them.