Which company owns MAC address prefix C4:7B:80?

MAC address prefix C4:7B:80 is registered to Protempis, LLC in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C4:7B:80 has a network interface built by Protempis, LLC.

What is the OUI C4:7B:80?

C4:7B:80 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Protempis, LLC. It covers every address from C4:7B:80:00:00:00 to C4:7B:80:FF:FF:FF, or 16,777,216 addresses in total. It is also written C4-7B-80.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in C4:7B:80:00:00:00 that is C4:7B:80 — 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 Protempis, LLC located?

Protempis, LLC is listed at 3333 Warrenville Road, Ste 200 Lisle IL US 60532-1999 in the IEEE OUI registry entry for C4:7B:80. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Protempis, LLC

MAC address prefix C4:7B:80 is registered to Protempis, LLC in the IEEE OUI registry. Any device whose MAC address begins with C4:7B:80 has a network interface built by Protempis, LLC. 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 C4:7B:80:00:00:00 to C4:7B:80:FF:FF:FF.

OUI prefix: C4:7B:80
Hyphen form: C4-7B-80
MAC range: C4:7B:80:00:00:00 – C4:7B:80:FF:FF:FF
Addresses in block: 16,777,216
Organization: Protempis, LLC
Address: 3333 Warrenville Road, Ste 200 Lisle IL US 60532-1999
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.

2022-09-05Assigned to "Protempis, LLC"
archived source →
2026-07-17Assigned to "Protempis, LLC"

Nearby in the registry

The prefixes assigned immediately before and after C4:7B:80:

FAQ

Which company owns MAC address prefix C4:7B:80?: MAC address prefix C4:7B:80 is registered to Protempis, LLC in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C4:7B:80 has a network interface built by Protempis, LLC.
What is the OUI C4:7B:80?: C4:7B:80 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Protempis, LLC. It covers every address from C4:7B:80:00:00:00 to C4:7B:80:FF:FF:FF, or 16,777,216 addresses in total. It is also written C4-7B-80.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in C4:7B:80:00:00:00 that is C4:7B:80 — 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 Protempis, LLC located?: Protempis, LLC is listed at 3333 Warrenville Road, Ste 200 Lisle IL US 60532-1999 in the IEEE OUI registry entry for C4:7B:80. This is the address the organization registered with the IEEE, which may differ from its current operating address.