Which company owns MAC address prefix C8:C7:91?

MAC address prefix C8:C7:91 is registered to Zero1.tv GmbH in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C8:C7:91 has a network interface built by Zero1.tv GmbH.

What is the OUI C8:C7:91?

C8:C7:91 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Zero1.tv GmbH. It covers every address from C8:C7:91:00:00:00 to C8:C7:91:FF:FF:FF, or 16,777,216 addresses in total. It is also written C8-C7-91.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in C8:C7:91:00:00:00 that is C8:C7:91 — 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 Zero1.tv GmbH located?

Zero1.tv GmbH is listed at Heinrich-Roller-Str. 16 B Berlin DE 10405 in the IEEE OUI registry entry for C8:C7:91. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Zero1.tv GmbH

MAC address prefix C8:C7:91 is registered to Zero1.tv GmbH in the IEEE OUI registry. Any device whose MAC address begins with C8:C7:91 has a network interface built by Zero1.tv 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 C8:C7:91:00:00:00 to C8:C7:91:FF:FF:FF.

OUI prefix: C8:C7:91
Hyphen form: C8-C7-91
MAC range: C8:C7:91:00:00:00 – C8:C7:91:FF:FF:FF
Addresses in block: 16,777,216
Organization: Zero1.tv GmbH
Address: Heinrich-Roller-Str. 16 B Berlin DE 10405
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 "Zero1.tv GmbH"
archived source →
2026-07-17Assigned to "Zero1.tv GmbH"

Nearby in the registry

The prefixes assigned immediately before and after C8:C7:91:

FAQ

Which company owns MAC address prefix C8:C7:91?: MAC address prefix C8:C7:91 is registered to Zero1.tv GmbH in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C8:C7:91 has a network interface built by Zero1.tv GmbH.
What is the OUI C8:C7:91?: C8:C7:91 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Zero1.tv GmbH. It covers every address from C8:C7:91:00:00:00 to C8:C7:91:FF:FF:FF, or 16,777,216 addresses in total. It is also written C8-C7-91.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in C8:C7:91:00:00:00 that is C8:C7:91 — 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 Zero1.tv GmbH located?: Zero1.tv GmbH is listed at Heinrich-Roller-Str. 16 B Berlin DE 10405 in the IEEE OUI registry entry for C8:C7:91. This is the address the organization registered with the IEEE, which may differ from its current operating address.