Which company owns MAC address prefix 00:1D:44?

MAC address prefix 00:1D:44 is registered to Krohne in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:1D:44 has a network interface built by Krohne.

What is the OUI 00:1D:44?

00:1D:44 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Krohne. It covers every address from 00:1D:44:00:00:00 to 00:1D:44:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-1D-44.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 00:1D:44:00:00:00 that is 00:1D:44 — 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 Krohne located?

Krohne is listed at Ludwig-Krohne-Str. 5 Duisburg DE 47058 in the IEEE OUI registry entry for 00:1D:44. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Krohne

MAC address prefix 00:1D:44 is registered to Krohne in the IEEE OUI registry. Any device whose MAC address begins with 00:1D:44 has a network interface built by Krohne. 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 00:1D:44:00:00:00 to 00:1D:44:FF:FF:FF.

OUI prefix: 00:1D:44
Hyphen form: 00-1D-44
MAC range: 00:1D:44:00:00:00 – 00:1D:44:FF:FF:FF
Addresses in block: 16,777,216
Organization: Krohne
Address: Ludwig-Krohne-Str. 5 Duisburg DE 47058
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 "KROHNE Messtechnik GmbH"
archived source →
2017-09-08Renamed from "KROHNE Messtechnik GmbH" to "Krohne"
archived source →
2026-07-17Assigned to "Krohne"

Nearby in the registry

The prefixes assigned immediately before and after 00:1D:44:

FAQ

Which company owns MAC address prefix 00:1D:44?: MAC address prefix 00:1D:44 is registered to Krohne in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:1D:44 has a network interface built by Krohne.
What is the OUI 00:1D:44?: 00:1D:44 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Krohne. It covers every address from 00:1D:44:00:00:00 to 00:1D:44:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-1D-44.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 00:1D:44:00:00:00 that is 00:1D:44 — 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 Krohne located?: Krohne is listed at Ludwig-Krohne-Str. 5 Duisburg DE 47058 in the IEEE OUI registry entry for 00:1D:44. This is the address the organization registered with the IEEE, which may differ from its current operating address.