Which company owns MAC address prefix 38:66:45?

MAC address prefix 38:66:45 is registered to OOSIC Technology CO.,Ltd in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 38:66:45 has a network interface built by OOSIC Technology CO.,Ltd.

What is the OUI 38:66:45?

38:66:45 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to OOSIC Technology CO.,Ltd. It covers every address from 38:66:45:00:00:00 to 38:66:45:FF:FF:FF, or 16,777,216 addresses in total. It is also written 38-66-45.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 38:66:45:00:00:00 that is 38:66:45 — 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 OOSIC Technology CO.,Ltd located?

OOSIC Technology CO.,Ltd is listed at 8F,No 1559, Zuchongzhi Road Shanghai CN 201203 in the IEEE OUI registry entry for 38:66:45. This is the address the organization registered with the IEEE, which may differ from its current operating address.

OOSIC Technology CO.,Ltd

MAC address prefix 38:66:45 is registered to OOSIC Technology CO.,Ltd in the IEEE OUI registry. Any device whose MAC address begins with 38:66:45 has a network interface built by OOSIC 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 38:66:45:00:00:00 to 38:66:45:FF:FF:FF.

OUI prefix: 38:66:45
Hyphen form: 38-66-45
MAC range: 38:66:45:00:00:00 – 38:66:45:FF:FF:FF
Addresses in block: 16,777,216
Organization: OOSIC Technology CO.,Ltd
Address: 8F,No 1559, Zuchongzhi Road Shanghai CN 201203
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 "OOSIC Technology CO.,Ltd"
archived source →
2026-07-17Assigned to "OOSIC Technology CO.,Ltd"

Nearby in the registry

The prefixes assigned immediately before and after 38:66:45:

FAQ

Which company owns MAC address prefix 38:66:45?: MAC address prefix 38:66:45 is registered to OOSIC Technology CO.,Ltd in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 38:66:45 has a network interface built by OOSIC Technology CO.,Ltd.
What is the OUI 38:66:45?: 38:66:45 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to OOSIC Technology CO.,Ltd. It covers every address from 38:66:45:00:00:00 to 38:66:45:FF:FF:FF, or 16,777,216 addresses in total. It is also written 38-66-45.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 38:66:45:00:00:00 that is 38:66:45 — 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 OOSIC Technology CO.,Ltd located?: OOSIC Technology CO.,Ltd is listed at 8F,No 1559, Zuchongzhi Road Shanghai CN 201203 in the IEEE OUI registry entry for 38:66:45. This is the address the organization registered with the IEEE, which may differ from its current operating address.