Which company owns MAC address prefix 3C:57:65?

MAC address prefix 3C:57:65 is registered to UNIONMAN TECHNOLOGY CO.,LTD in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 3C:57:65 has a network interface built by UNIONMAN TECHNOLOGY CO.,LTD.

What is the OUI 3C:57:65?

3C:57:65 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to UNIONMAN TECHNOLOGY CO.,LTD. It covers every address from 3C:57:65:00:00:00 to 3C:57:65:FF:FF:FF, or 16,777,216 addresses in total. It is also written 3C-57-65.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 3C:57:65:00:00:00 that is 3C:57:65 — 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 UNIONMAN TECHNOLOGY CO.,LTD located?

UNIONMAN TECHNOLOGY CO.,LTD is listed at No.5,Huitai Road,Huinan High-Tech Park,Huiao Highway Huizhou Guangdong CN 516025 in the IEEE OUI registry entry for 3C:57:65. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does UNIONMAN TECHNOLOGY CO.,LTD own?

UNIONMAN TECHNOLOGY CO.,LTD holds 12 OUI prefixes in the IEEE registry, of which 3C:57:65 is one. A device made by UNIONMAN TECHNOLOGY CO.,LTD could carry a MAC address from any of them.

UNIONMAN TECHNOLOGY CO.,LTD

MAC address prefix 3C:57:65 is registered to UNIONMAN TECHNOLOGY CO.,LTD in the IEEE OUI registry. Any device whose MAC address begins with 3C:57:65 has a network interface built by UNIONMAN TECHNOLOGY 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 3C:57:65:00:00:00 to 3C:57:65:FF:FF:FF.

OUI prefix: 3C:57:65
Hyphen form: 3C-57-65
MAC range: 3C:57:65:00:00:00 – 3C:57:65:FF:FF:FF
Addresses in block: 16,777,216
Organization: UNIONMAN TECHNOLOGY CO.,LTD
Address: No.5,Huitai Road,Huinan High-Tech Park,Huiao Highway Huizhou Guangdong CN 516025
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.

Other prefixes from UNIONMAN TECHNOLOGY CO.,LTD

UNIONMAN TECHNOLOGY CO.,LTD holds 12 OUI prefixes in total. A device with this exact prefix could just as well carry any of these:

Assignment history (2)

The IEEE registry publishes current state only — this is the change record we've kept since we started tracking it daily.

2024-08-15Assigned to "UNIONMAN TECHNOLOGY CO.,LTD"
archived source →
2026-07-17Assigned to "UNIONMAN TECHNOLOGY CO.,LTD"

Nearby in the registry

The prefixes assigned immediately before and after 3C:57:65:

FAQ

Which company owns MAC address prefix 3C:57:65?: MAC address prefix 3C:57:65 is registered to UNIONMAN TECHNOLOGY CO.,LTD in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 3C:57:65 has a network interface built by UNIONMAN TECHNOLOGY CO.,LTD.
What is the OUI 3C:57:65?: 3C:57:65 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to UNIONMAN TECHNOLOGY CO.,LTD. It covers every address from 3C:57:65:00:00:00 to 3C:57:65:FF:FF:FF, or 16,777,216 addresses in total. It is also written 3C-57-65.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 3C:57:65:00:00:00 that is 3C:57:65 — 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 UNIONMAN TECHNOLOGY CO.,LTD located?: UNIONMAN TECHNOLOGY CO.,LTD is listed at No.5,Huitai Road,Huinan High-Tech Park,Huiao Highway Huizhou Guangdong CN 516025 in the IEEE OUI registry entry for 3C:57:65. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does UNIONMAN TECHNOLOGY CO.,LTD own?: UNIONMAN TECHNOLOGY CO.,LTD holds 12 OUI prefixes in the IEEE registry, of which 3C:57:65 is one. A device made by UNIONMAN TECHNOLOGY CO.,LTD could carry a MAC address from any of them.