Which company owns MAC address prefix E0:91:3C?

MAC address prefix E0:91:3C is registered to Kyeungin CNS Co., Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with E0:91:3C has a network interface built by Kyeungin CNS Co., Ltd..

What is the OUI E0:91:3C?

E0:91:3C is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Kyeungin CNS Co., Ltd.. It covers every address from E0:91:3C:00:00:00 to E0:91:3C:FF:FF:FF, or 16,777,216 addresses in total. It is also written E0-91-3C.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in E0:91:3C:00:00:00 that is E0:91:3C — 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 Kyeungin CNS Co., Ltd. located?

Kyeungin CNS Co., Ltd. is listed at 13, Gyeongin-ro, Sosa-gu Bucheon-si Gyeonggi-do KR 14730 in the IEEE OUI registry entry for E0:91:3C. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Kyeungin CNS Co., Ltd.

MAC address prefix E0:91:3C is registered to Kyeungin CNS Co., Ltd. in the IEEE OUI registry. Any device whose MAC address begins with E0:91:3C has a network interface built by Kyeungin CNS Co., Ltd.. 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 E0:91:3C:00:00:00 to E0:91:3C:FF:FF:FF.

OUI prefix: E0:91:3C
Hyphen form: E0-91-3C
MAC range: E0:91:3C:00:00:00 – E0:91:3C:FF:FF:FF
Addresses in block: 16,777,216
Organization: Kyeungin CNS Co., Ltd.
Address: 13, Gyeongin-ro, Sosa-gu Bucheon-si Gyeonggi-do KR 14730
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.

2020-11-28Assigned to "Kyeungin CNS Co., Ltd."
archived source →
2026-07-17Assigned to "Kyeungin CNS Co., Ltd."

Nearby in the registry

The prefixes assigned immediately before and after E0:91:3C:

FAQ

Which company owns MAC address prefix E0:91:3C?: MAC address prefix E0:91:3C is registered to Kyeungin CNS Co., Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with E0:91:3C has a network interface built by Kyeungin CNS Co., Ltd..
What is the OUI E0:91:3C?: E0:91:3C is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Kyeungin CNS Co., Ltd.. It covers every address from E0:91:3C:00:00:00 to E0:91:3C:FF:FF:FF, or 16,777,216 addresses in total. It is also written E0-91-3C.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in E0:91:3C:00:00:00 that is E0:91:3C — 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 Kyeungin CNS Co., Ltd. located?: Kyeungin CNS Co., Ltd. is listed at 13, Gyeongin-ro, Sosa-gu Bucheon-si Gyeonggi-do KR 14730 in the IEEE OUI registry entry for E0:91:3C. This is the address the organization registered with the IEEE, which may differ from its current operating address.