GD Midea Air-Conditioning Equipment Co., Ltd. — 52 prefixes (51 MA-L + 1 MA-M)

Midea's IEEE MAC footprint is one of the largest of any home-appliance maker: 51 MA-L (24-bit OUI) blocks plus a single MA-M (28-bit) block. Fifty MA-L blocks are registered to "GD Midea Air-Conditioning Equipment Co.,Ltd." and one (38:21:87) to the parent "Midea Group Co., Ltd."; the lone MA-M block (D0:AA:5F:7) belongs to "GD Midea Heating & Ventilating Equipment Co., Ltd". All are Guangdong, China entities clustered around the Midea Global Innovation Center in Beijiao Town, Shunde, Foshan (postal 528311/528000). The registrant name emphasizing air conditioning is misleading for network triage: these prefixes cover Midea's whole M-Smart connected-appliance range — air conditioners, fans, heat pumps, refrigerators, washing machines, dishwashers, microwave ovens, water heaters, air purifiers, and dehumidifiers — not just HVAC. Midea devices use the proprietary M-Smart protocol over the local LAN (TCP port 6444) with cloud-paired token+key credentials, and make persistent outbound connections to Midea cloud infrastructure in China. The practical consequence: a Midea OUI on a home or SMB network almost certainly identifies a Wi-Fi consumer appliance (AC most common, but washer/fridge/dehumidifier are all plausible), and the primary security consideration is data transmission to Chinese cloud servers rather than any known active exploit — no public CVEs surfaced in this pass. Midea uses its own registered prefixes on its Wi-Fi modules rather than surfacing under a chipset vendor's OUI. One data trap: 38:D6:20 ("Limidea Concept Pte. Ltd.", Singapore) matches on substring but is an unrelated entity, not Midea.

IEEE assignment

51 MA-L prefixes (50 → GD Midea Air-Conditioning Equipment Co.,Ltd.; 1 → Midea Group Co., Ltd. at 38:21:87) + 1 MA-M prefix (D0:AA:5F:7 → GD Midea Heating & Ventilating Equipment Co., Ltd) [Confirmed] — IEEE oui.csv / mam.csv (cached registries); corroborated maclookup.app, hwaddress.com

Registry / block size

MA-L (24-bit OUI) for the 51 blocks; MA-M (28-bit) for D0:AA:5F:7. No MA-S (36-bit) Midea entries found in oui36.csv. [Confirmed] — IEEE registries (oui.csv, mam.csv, oui36.csv)

HQ / country

Midea Global Innovation Center, Beijiao Town, Shunde, Foshan, Guangdong 528311, CN (most blocks). Midea Group Co., Ltd. (38:21:87): No. 6 Midea Avenue, Foshan, Guangdong 528311, CN. GD Midea Heating & Ventilating (MA-M): Penglai Road industrial avenue, Beijiao Town, Shunde, Foshan 528000, CN. [Confirmed] — IEEE registry rows; maclookup.app

Company status

active. Midea Group Co., Ltd. founded 1968, Foshan; publicly listed (Shenzhen Stock Exchange: 000333); GD Midea Air-Conditioning Equipment Co.,Ltd. is a wholly owned subsidiary and the IEEE registrant for the bulk of the MAC estate. [Confirmed] — en.wikipedia.org/wiki/Midea_Group

Device types

air conditioners (primary, per registrant name), fans, heaters, heat pumps, refrigerators, washing machines, dishwashers, microwave ovens, water heaters, air purifiers, dehumidifiers, humidifiers, and other connected M-Smart home appliances [Confirmed] — github.com/georgezhao2010/midea_ac_lan, midea.com

Notable products

M-Smart connected home-appliance range; Midea also owns KUKA (German robotics), Little Swan, Hualing, MDV, Pelonis brand lines [Likely] — en.wikipedia.org/wiki/Midea_Group

Verified sample prefixes (MA-L, GD Midea Air-Conditioning Equipment Co.,Ltd.)

80:76:C2, FC:DF:00, 9C:C1:2D, 10:2C:8D, 70:86:CE, A8:40:7D, F8:D5:54 [Confirmed] — IEEE oui.csv / maclookup.app

Distinct registrant prefix

38:21:87 → Midea Group Co., Ltd. (parent entity, MA-L) [Confirmed] — IEEE oui.csv; cleancss.com/mac-lookup/38-21-87

No-date note

IEEE publishes NO assignment/registration date for OUI/MAC blocks. No date is present in the cached oui.csv, mam.csv, or oui36.csv. Third-party per-prefix timestamps (e.g. FC:DF:00 "June 2022", 18:41:C3 "January 2025" on maclookup.app) are database scrape artifacts, not IEEE facts — do not publish them as registration dates. [Confirmed] — IEEE OUI data schema; maclookup.app

Protocol / port

M-Smart local control over LAN TCP port 6444; requires cloud-retrieved token+key credentials. Third-party Home Assistant integrations exist (midea_ac_lan). [Likely] — github.com/georgezhao2010/midea_ac_lan, github.com/wuwentao/midea_ac_lan

Security context

Chinese OEM/ODM; smart appliances communicate with Midea cloud and can transmit data outside the EU/US including to China (per Midea UK privacy policy). Midea operates a PSIRT (iotsecurity@midea.com), was the first China company to achieve UL IoT Security Rating (silver, 2020, select AC/dehumidifier lines), and holds ioXt Alliance certification for seven appliances. No public CVEs surfaced this pass. Primary concern is data residency, not known exploits. [Likely] — ul.com, businesswire.com, mideauk.co.uk/privacy, midea.com/global/psti/vulnerability-reporting

Data trap

38:D6:20 ("Limidea Concept Pte. Ltd.", Singapore) is NOT Midea — substring match on an unrelated entity. [Confirmed] — IEEE oui.csv

Related vendors

KUKA (owned), Little Swan (owned), Carrier Global / Toshiba Carrier (HVAC partners/JV), Comfortstar [Likely] — en.wikipedia.org/wiki/Midea_Group

Analyst note

52 blocks give Midea one of the largest appliance-vendor OUI footprints. The registrant name reflects the subsidiary, but the OUI covers the entire M-Smart range. On a home/SMB network a Midea OUI almost certainly indicates a Wi-Fi appliance making persistent outbound cloud connections to Midea infrastructure in China — segment accordingly if data residency matters.