Which company owns MAC address prefix 80:34:57?

MAC address prefix 80:34:57 is registered to OT Systems Limited in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 80:34:57 has a network interface built by OT Systems Limited.

What is the OUI 80:34:57?

80:34:57 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to OT Systems Limited. It covers every address from 80:34:57:00:00:00 to 80:34:57:FF:FF:FF, or 16,777,216 addresses in total. It is also written 80-34-57.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 80:34:57:00:00:00 that is 80:34:57 — 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 OT Systems Limited located?

OT Systems Limited is listed at Unit 1023, 10/F., Landmark North, Sheung Shui, N. T. HK in the IEEE OUI registry entry for 80:34:57. This is the address the organization registered with the IEEE, which may differ from its current operating address.

OT Systems Limited

MAC address prefix 80:34:57 is registered to OT Systems Limited in the IEEE OUI registry. Any device whose MAC address begins with 80:34:57 has a network interface built by OT Systems Limited. 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 80:34:57:00:00:00 to 80:34:57:FF:FF:FF.

OUI prefix: 80:34:57
Hyphen form: 80-34-57
MAC range: 80:34:57:00:00:00 – 80:34:57:FF:FF:FF
Addresses in block: 16,777,216
Organization: OT Systems Limited
Address: Unit 1023, 10/F., Landmark North, Sheung Shui, N. T. HK
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 "OT Systems Limited"
archived source →
2026-07-17Assigned to "OT Systems Limited"

Nearby in the registry

The prefixes assigned immediately before and after 80:34:57:

FAQ

Which company owns MAC address prefix 80:34:57?: MAC address prefix 80:34:57 is registered to OT Systems Limited in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 80:34:57 has a network interface built by OT Systems Limited.
What is the OUI 80:34:57?: 80:34:57 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to OT Systems Limited. It covers every address from 80:34:57:00:00:00 to 80:34:57:FF:FF:FF, or 16,777,216 addresses in total. It is also written 80-34-57.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 80:34:57:00:00:00 that is 80:34:57 — 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 OT Systems Limited located?: OT Systems Limited is listed at Unit 1023, 10/F., Landmark North, Sheung Shui, N. T. HK in the IEEE OUI registry entry for 80:34:57. This is the address the organization registered with the IEEE, which may differ from its current operating address.