Which company owns MAC address prefix C4:E1:7C?

MAC address prefix C4:E1:7C is registered to U2S co. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C4:E1:7C has a network interface built by U2S co..

What is the OUI C4:E1:7C?

C4:E1:7C is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to U2S co.. It covers every address from C4:E1:7C:00:00:00 to C4:E1:7C:FF:FF:FF, or 16,777,216 addresses in total. It is also written C4-E1-7C.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in C4:E1:7C:00:00:00 that is C4:E1:7C — 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 U2S co. located?

U2S co. is listed at 104-706, SK Ventium Building, 522, Dangjeong-Dong Gunpo-si Geonggi-do KR 435-776 in the IEEE OUI registry entry for C4:E1:7C. This is the address the organization registered with the IEEE, which may differ from its current operating address.

U2S co.

MAC address prefix C4:E1:7C is registered to U2S co. in the IEEE OUI registry. Any device whose MAC address begins with C4:E1:7C has a network interface built by U2S co.. 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:E1:7C:00:00:00 to C4:E1:7C:FF:FF:FF.

OUI prefix: C4:E1:7C
Hyphen form: C4-E1-7C
MAC range: C4:E1:7C:00:00:00 – C4:E1:7C:FF:FF:FF
Addresses in block: 16,777,216
Organization: U2S co.
Address: 104-706, SK Ventium Building, 522, Dangjeong-Dong Gunpo-si Geonggi-do KR 435-776
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 "U2S co."
archived source →
2026-07-17Assigned to "U2S co."

Nearby in the registry

The prefixes assigned immediately before and after C4:E1:7C:

FAQ

Which company owns MAC address prefix C4:E1:7C?: MAC address prefix C4:E1:7C is registered to U2S co. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C4:E1:7C has a network interface built by U2S co..
What is the OUI C4:E1:7C?: C4:E1:7C is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to U2S co.. It covers every address from C4:E1:7C:00:00:00 to C4:E1:7C:FF:FF:FF, or 16,777,216 addresses in total. It is also written C4-E1-7C.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in C4:E1:7C:00:00:00 that is C4:E1:7C — 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 U2S co. located?: U2S co. is listed at 104-706, SK Ventium Building, 522, Dangjeong-Dong Gunpo-si Geonggi-do KR 435-776 in the IEEE OUI registry entry for C4:E1:7C. This is the address the organization registered with the IEEE, which may differ from its current operating address.