Which company owns MAC address prefix 00:18:83?

MAC address prefix 00:18:83 is registered to FORMOSA21 INC. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:18:83 has a network interface built by FORMOSA21 INC..

What is the OUI 00:18:83?

00:18:83 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to FORMOSA21 INC.. It covers every address from 00:18:83:00:00:00 to 00:18:83:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-18-83.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 00:18:83:00:00:00 that is 00:18:83 — 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 FORMOSA21 INC. located?

FORMOSA21 INC. is listed at 8F-6, NO.351, CHUNG SHAN RD., SEC.2 TAIPEI TW 235 in the IEEE OUI registry entry for 00:18:83. This is the address the organization registered with the IEEE, which may differ from its current operating address.

FORMOSA21 INC.

MAC address prefix 00:18:83 is registered to FORMOSA21 INC. in the IEEE OUI registry. Any device whose MAC address begins with 00:18:83 has a network interface built by FORMOSA21 INC.. 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 00:18:83:00:00:00 to 00:18:83:FF:FF:FF.

OUI prefix: 00:18:83
Hyphen form: 00-18-83
MAC range: 00:18:83:00:00:00 – 00:18:83:FF:FF:FF
Addresses in block: 16,777,216
Organization: FORMOSA21 INC.
Address: 8F-6, NO.351, CHUNG SHAN RD., SEC.2 TAIPEI TW 235
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 "FORMOSA21 INC."
archived source →
2026-07-17Assigned to "FORMOSA21 INC."

Nearby in the registry

The prefixes assigned immediately before and after 00:18:83:

FAQ

Which company owns MAC address prefix 00:18:83?: MAC address prefix 00:18:83 is registered to FORMOSA21 INC. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:18:83 has a network interface built by FORMOSA21 INC..
What is the OUI 00:18:83?: 00:18:83 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to FORMOSA21 INC.. It covers every address from 00:18:83:00:00:00 to 00:18:83:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-18-83.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 00:18:83:00:00:00 that is 00:18:83 — 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 FORMOSA21 INC. located?: FORMOSA21 INC. is listed at 8F-6, NO.351, CHUNG SHAN RD., SEC.2 TAIPEI TW 235 in the IEEE OUI registry entry for 00:18:83. This is the address the organization registered with the IEEE, which may differ from its current operating address.