Which company owns MAC address prefix 0C:21:38?

MAC address prefix 0C:21:38 is registered to Hengstler GmbH in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 0C:21:38 has a network interface built by Hengstler GmbH.

What is the OUI 0C:21:38?

0C:21:38 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Hengstler GmbH. It covers every address from 0C:21:38:00:00:00 to 0C:21:38:FF:FF:FF, or 16,777,216 addresses in total. It is also written 0C-21-38.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 0C:21:38:00:00:00 that is 0C:21:38 — 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 Hengstler GmbH located?

Hengstler GmbH is listed at Uhlandstrasse49 Aldingen BW DE 78554 in the IEEE OUI registry entry for 0C:21:38. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Hengstler GmbH

MAC address prefix 0C:21:38 is registered to Hengstler GmbH in the IEEE OUI registry. Any device whose MAC address begins with 0C:21:38 has a network interface built by Hengstler GmbH. 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 0C:21:38:00:00:00 to 0C:21:38:FF:FF:FF.

OUI prefix: 0C:21:38
Hyphen form: 0C-21-38
MAC range: 0C:21:38:00:00:00 – 0C:21:38:FF:FF:FF
Addresses in block: 16,777,216
Organization: Hengstler GmbH
Address: Uhlandstrasse49 Aldingen BW DE 78554
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.

2018-12-21Assigned to "Hengstler GmbH"
archived source →
2026-07-17Assigned to "Hengstler GmbH"

Nearby in the registry

The prefixes assigned immediately before and after 0C:21:38:

FAQ

Which company owns MAC address prefix 0C:21:38?: MAC address prefix 0C:21:38 is registered to Hengstler GmbH in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 0C:21:38 has a network interface built by Hengstler GmbH.
What is the OUI 0C:21:38?: 0C:21:38 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Hengstler GmbH. It covers every address from 0C:21:38:00:00:00 to 0C:21:38:FF:FF:FF, or 16,777,216 addresses in total. It is also written 0C-21-38.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 0C:21:38:00:00:00 that is 0C:21:38 — 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 Hengstler GmbH located?: Hengstler GmbH is listed at Uhlandstrasse49 Aldingen BW DE 78554 in the IEEE OUI registry entry for 0C:21:38. This is the address the organization registered with the IEEE, which may differ from its current operating address.