Which company owns MAC address prefix 00:07:3F?

MAC address prefix 00:07:3F is registered to Woojyun Systec Co., Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:07:3F has a network interface built by Woojyun Systec Co., Ltd..

What is the OUI 00:07:3F?

00:07:3F is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Woojyun Systec Co., Ltd.. It covers every address from 00:07:3F:00:00:00 to 00:07:3F:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-07-3F.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 00:07:3F:00:00:00 that is 00:07:3F — 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 Woojyun Systec Co., Ltd. located?

Woojyun Systec Co., Ltd. is listed at 4F Han Yang B/D, Yoido-dong Seoul KR 150-010 in the IEEE OUI registry entry for 00:07:3F. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Woojyun Systec Co., Ltd.

MAC address prefix 00:07:3F is registered to Woojyun Systec Co., Ltd. in the IEEE OUI registry. Any device whose MAC address begins with 00:07:3F has a network interface built by Woojyun Systec 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 00:07:3F:00:00:00 to 00:07:3F:FF:FF:FF.

OUI prefix: 00:07:3F
Hyphen form: 00-07-3F
MAC range: 00:07:3F:00:00:00 – 00:07:3F:FF:FF:FF
Addresses in block: 16,777,216
Organization: Woojyun Systec Co., Ltd.
Address: 4F Han Yang B/D, Yoido-dong Seoul KR 150-010
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 "Woojyun Systec Co., Ltd."
archived source →
2026-07-17Assigned to "Woojyun Systec Co., Ltd."

Nearby in the registry

The prefixes assigned immediately before and after 00:07:3F:

FAQ

Which company owns MAC address prefix 00:07:3F?: MAC address prefix 00:07:3F is registered to Woojyun Systec Co., Ltd. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:07:3F has a network interface built by Woojyun Systec Co., Ltd..
What is the OUI 00:07:3F?: 00:07:3F is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Woojyun Systec Co., Ltd.. It covers every address from 00:07:3F:00:00:00 to 00:07:3F:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-07-3F.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 00:07:3F:00:00:00 that is 00:07:3F — 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 Woojyun Systec Co., Ltd. located?: Woojyun Systec Co., Ltd. is listed at 4F Han Yang B/D, Yoido-dong Seoul KR 150-010 in the IEEE OUI registry entry for 00:07:3F. This is the address the organization registered with the IEEE, which may differ from its current operating address.