Which company owns MAC address prefix 38:5F:C3?

MAC address prefix 38:5F:C3 is registered to Yu Jeong System, Co.Ltd in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 38:5F:C3 has a network interface built by Yu Jeong System, Co.Ltd.

What is the OUI 38:5F:C3?

38:5F:C3 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Yu Jeong System, Co.Ltd. It covers every address from 38:5F:C3:00:00:00 to 38:5F:C3:FF:FF:FF, or 16,777,216 addresses in total. It is also written 38-5F-C3.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 38:5F:C3:00:00:00 that is 38:5F:C3 — 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 Yu Jeong System, Co.Ltd located?

Yu Jeong System, Co.Ltd is listed at #503, Dong il B/D, 826, Guro-3dong, Seoul KR 152-879 in the IEEE OUI registry entry for 38:5F:C3. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Yu Jeong System, Co.Ltd

MAC address prefix 38:5F:C3 is registered to Yu Jeong System, Co.Ltd in the IEEE OUI registry. Any device whose MAC address begins with 38:5F:C3 has a network interface built by Yu Jeong System, 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 38:5F:C3:00:00:00 to 38:5F:C3:FF:FF:FF.

OUI prefix: 38:5F:C3
Hyphen form: 38-5F-C3
MAC range: 38:5F:C3:00:00:00 – 38:5F:C3:FF:FF:FF
Addresses in block: 16,777,216
Organization: Yu Jeong System, Co.Ltd
Address: #503, Dong il B/D, 826, Guro-3dong, Seoul KR 152-879
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 "Yu Jeong System, Co.Ltd"
archived source →
2026-07-17Assigned to "Yu Jeong System, Co.Ltd"

Nearby in the registry

The prefixes assigned immediately before and after 38:5F:C3:

FAQ

Which company owns MAC address prefix 38:5F:C3?: MAC address prefix 38:5F:C3 is registered to Yu Jeong System, Co.Ltd in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 38:5F:C3 has a network interface built by Yu Jeong System, Co.Ltd.
What is the OUI 38:5F:C3?: 38:5F:C3 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Yu Jeong System, Co.Ltd. It covers every address from 38:5F:C3:00:00:00 to 38:5F:C3:FF:FF:FF, or 16,777,216 addresses in total. It is also written 38-5F-C3.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 38:5F:C3:00:00:00 that is 38:5F:C3 — 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 Yu Jeong System, Co.Ltd located?: Yu Jeong System, Co.Ltd is listed at #503, Dong il B/D, 826, Guro-3dong, Seoul KR 152-879 in the IEEE OUI registry entry for 38:5F:C3. This is the address the organization registered with the IEEE, which may differ from its current operating address.