Which company owns MAC address prefix 8C:31:E2?

MAC address prefix 8C:31:E2 is registered to DAYOUPLUS in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 8C:31:E2 has a network interface built by DAYOUPLUS.

What is the OUI 8C:31:E2?

8C:31:E2 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to DAYOUPLUS. It covers every address from 8C:31:E2:00:00:00 to 8C:31:E2:FF:FF:FF, or 16,777,216 addresses in total. It is also written 8C-31-E2.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 8C:31:E2:00:00:00 that is 8C:31:E2 — 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 DAYOUPLUS located?

DAYOUPLUS is listed at 3F 509, Dunchon-daero, Jungwon-gu, Seongnam-si, Gyeonggi-do, Republic of Korea Seongnam-si Gyeonggi-do KR 13217 in the IEEE OUI registry entry for 8C:31:E2. This is the address the organization registered with the IEEE, which may differ from its current operating address.

DAYOUPLUS

MAC address prefix 8C:31:E2 is registered to DAYOUPLUS in the IEEE OUI registry. Any device whose MAC address begins with 8C:31:E2 has a network interface built by DAYOUPLUS. 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 8C:31:E2:00:00:00 to 8C:31:E2:FF:FF:FF.

OUI prefix: 8C:31:E2
Hyphen form: 8C-31-E2
MAC range: 8C:31:E2:00:00:00 – 8C:31:E2:FF:FF:FF
Addresses in block: 16,777,216
Organization: DAYOUPLUS
Address: 3F 509, Dunchon-daero, Jungwon-gu, Seongnam-si, Gyeonggi-do, Republic of Korea Seongnam-si Gyeonggi-do KR 13217
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.

2021-02-25Assigned to "DAYOUPLUS"
archived source →
2026-07-17Assigned to "DAYOUPLUS"

Nearby in the registry

The prefixes assigned immediately before and after 8C:31:E2:

FAQ

Which company owns MAC address prefix 8C:31:E2?: MAC address prefix 8C:31:E2 is registered to DAYOUPLUS in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 8C:31:E2 has a network interface built by DAYOUPLUS.
What is the OUI 8C:31:E2?: 8C:31:E2 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to DAYOUPLUS. It covers every address from 8C:31:E2:00:00:00 to 8C:31:E2:FF:FF:FF, or 16,777,216 addresses in total. It is also written 8C-31-E2.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 8C:31:E2:00:00:00 that is 8C:31:E2 — 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 DAYOUPLUS located?: DAYOUPLUS is listed at 3F 509, Dunchon-daero, Jungwon-gu, Seongnam-si, Gyeonggi-do, Republic of Korea Seongnam-si Gyeonggi-do KR 13217 in the IEEE OUI registry entry for 8C:31:E2. This is the address the organization registered with the IEEE, which may differ from its current operating address.