Which company owns MAC address prefix 00:20:3D?

MAC address prefix 00:20:3D is registered to Honeywell Environmental & Combustion Controls in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:20:3D has a network interface built by Honeywell Environmental & Combustion Controls.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 00:20:3D:00:00:00 that is 00:20:3D — 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

MAC address prefix 00:20:3D is registered to Honeywell Environmental & Combustion Controls in the IEEE OUI registry. Any device whose MAC address begins with 00:20:3D has a network interface built by Honeywell Environmental & Combustion Controls. 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 00:20:3D:00:00:00 to 00:20:3D:FF:FF:FF.

OUI prefix: 00:20:3D
Hyphen form: 00-20-3D
MAC range: 00:20:3D:00:00:00 – 00:20:3D:FF:FF:FF
Addresses in block: 16,777,216
Organization: Honeywell Environmental & Combustion Controls
Address: 1985 Douglas Drive Golden Valley MN US 55422
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 (3)

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 ECC"
archived source →
2018-12-21Renamed from "Honeywell ECC" to "Honeywell Environmental & Combustion Controls"
archived source →
2026-07-17Assigned to "Honeywell Environmental & Combustion Controls"

Nearby in the registry

The prefixes assigned immediately before and after 00:20:3D:

FAQ

Which company owns MAC address prefix 00:20:3D?: MAC address prefix 00:20:3D is registered to Honeywell Environmental & Combustion Controls in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:20:3D has a network interface built by Honeywell Environmental & Combustion Controls.
What is the OUI 00:20:3D?: 00:20:3D is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Honeywell Environmental & Combustion Controls. It covers every address from 00:20:3D:00:00:00 to 00:20:3D:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-20-3D.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 00:20:3D:00:00:00 that is 00:20:3D — 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 located?: Honeywell Environmental & Combustion Controls is listed at 1985 Douglas Drive Golden Valley MN US 55422 in the IEEE OUI registry entry for 00:20:3D. This is the address the organization registered with the IEEE, which may differ from its current operating address.