Which company owns MAC address prefix 20:57:AF?

MAC address prefix 20:57:AF is registered to Shenzhen FH-NET OPTOELECTRONICS CO.,LTD in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 20:57:AF has a network interface built by Shenzhen FH-NET OPTOELECTRONICS CO.,LTD.

What is the OUI 20:57:AF?

20:57:AF is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Shenzhen FH-NET OPTOELECTRONICS CO.,LTD. It covers every address from 20:57:AF:00:00:00 to 20:57:AF:FF:FF:FF, or 16,777,216 addresses in total. It is also written 20-57-AF.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 20:57:AF:00:00:00 that is 20:57:AF — 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 Shenzhen FH-NET OPTOELECTRONICS CO.,LTD located?

Shenzhen FH-NET OPTOELECTRONICS CO.,LTD is listed at 5/F Building D1 TCL International E City NO.1001 Zhong shan yuan Rd, Nanshan District Shenzhen china Shenzhen GuangDong CN 518055 in the IEEE OUI registry entry for 20:57:AF. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Shenzhen FH-NET OPTOELECTRONICS CO.,LTD

MAC address prefix 20:57:AF is registered to Shenzhen FH-NET OPTOELECTRONICS CO.,LTD in the IEEE OUI registry. Any device whose MAC address begins with 20:57:AF has a network interface built by Shenzhen FH-NET OPTOELECTRONICS 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 20:57:AF:00:00:00 to 20:57:AF:FF:FF:FF.

OUI prefix: 20:57:AF
Hyphen form: 20-57-AF
MAC range: 20:57:AF:00:00:00 – 20:57:AF:FF:FF:FF
Addresses in block: 16,777,216
Organization: Shenzhen FH-NET OPTOELECTRONICS CO.,LTD
Address: 5/F Building D1 TCL International E City NO.1001 Zhong shan yuan Rd, Nanshan District Shenzhen china Shenzhen GuangDong CN 518055
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 "Shenzhen FH-NET OPTOELECTRONICS CO.,LTD"
archived source →
2026-07-17Assigned to "Shenzhen FH-NET OPTOELECTRONICS CO.,LTD"

Nearby in the registry

The prefixes assigned immediately before and after 20:57:AF:

FAQ

Which company owns MAC address prefix 20:57:AF?: MAC address prefix 20:57:AF is registered to Shenzhen FH-NET OPTOELECTRONICS CO.,LTD in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 20:57:AF has a network interface built by Shenzhen FH-NET OPTOELECTRONICS CO.,LTD.
What is the OUI 20:57:AF?: 20:57:AF is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Shenzhen FH-NET OPTOELECTRONICS CO.,LTD. It covers every address from 20:57:AF:00:00:00 to 20:57:AF:FF:FF:FF, or 16,777,216 addresses in total. It is also written 20-57-AF.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 20:57:AF:00:00:00 that is 20:57:AF — 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 Shenzhen FH-NET OPTOELECTRONICS CO.,LTD located?: Shenzhen FH-NET OPTOELECTRONICS CO.,LTD is listed at 5/F Building D1 TCL International E City NO.1001 Zhong shan yuan Rd, Nanshan District Shenzhen china Shenzhen GuangDong CN 518055 in the IEEE OUI registry entry for 20:57:AF. This is the address the organization registered with the IEEE, which may differ from its current operating address.