Which company owns MAC address prefix DC:B3:B4?

MAC address prefix DC:B3:B4 is registered to Honeywell Environmental & Combustion Controls (Tianjin) Co., Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with DC:B3:B4 has a network interface built by Honeywell Environmental & Combustion Controls (Tianjin) Co., Ltd..

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in DC:B3:B4:00:00:00 that is DC:B3:B4 — 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.

Honeywell Environmental & Combustion Controls (Tianjin) Co., Ltd.

MAC address prefix DC:B3:B4 is registered to Honeywell Environmental & Combustion Controls (Tianjin) Co., Ltd. in the IEEE OUI registry. Any device whose MAC address begins with DC:B3:B4 has a network interface built by Honeywell Environmental & Combustion Controls (Tianjin) 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 DC:B3:B4:00:00:00 to DC:B3:B4:FF:FF:FF.

OUI prefix: DC:B3:B4
Hyphen form: DC-B3-B4
MAC range: DC:B3:B4:00:00:00 – DC:B3:B4:FF:FF:FF
Addresses in block: 16,777,216
Organization: Honeywell Environmental & Combustion Controls (Tianjin) Co., Ltd.
Address: 158 Nan Hai Road, TEDA Tianjin CN 300457
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 "Honeywell Environmental & Combustion Controls (Tianjin) Co., Ltd."
archived source →
2026-07-17Assigned to "Honeywell Environmental & Combustion Controls (Tianjin) Co., Ltd."

Nearby in the registry

The prefixes assigned immediately before and after DC:B3:B4:

FAQ

Which company owns MAC address prefix DC:B3:B4?: MAC address prefix DC:B3:B4 is registered to Honeywell Environmental & Combustion Controls (Tianjin) Co., Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with DC:B3:B4 has a network interface built by Honeywell Environmental & Combustion Controls (Tianjin) Co., Ltd..
What is the OUI DC:B3:B4?: DC:B3:B4 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Honeywell Environmental & Combustion Controls (Tianjin) Co., Ltd.. It covers every address from DC:B3:B4:00:00:00 to DC:B3:B4:FF:FF:FF, or 16,777,216 addresses in total. It is also written DC-B3-B4.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in DC:B3:B4:00:00:00 that is DC:B3:B4 — 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 Honeywell Environmental & Combustion Controls (Tianjin) Co., Ltd. located?: Honeywell Environmental & Combustion Controls (Tianjin) Co., Ltd. is listed at 158 Nan Hai Road, TEDA Tianjin CN 300457 in the IEEE OUI registry entry for DC:B3:B4. This is the address the organization registered with the IEEE, which may differ from its current operating address.