Which company owns MAC address prefix 3C:7C:3F?

MAC address prefix 3C:7C:3F is registered to ASUSTek COMPUTER INC. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 3C:7C:3F has a network interface built by ASUSTek COMPUTER INC..

What is the OUI 3C:7C:3F?

3C:7C:3F is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to ASUSTek COMPUTER INC.. It covers every address from 3C:7C:3F:00:00:00 to 3C:7C:3F:FF:FF:FF, or 16,777,216 addresses in total. It is also written 3C-7C-3F.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 3C:7C:3F:00:00:00 that is 3C:7C:3F — 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 ASUSTek COMPUTER INC. located?

ASUSTek COMPUTER INC. is listed at 15,Li-Te Rd., Peitou, Taipei 112, Taiwan Taipei Taiwan TW 112 in the IEEE OUI registry entry for 3C:7C:3F. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does ASUSTek COMPUTER INC. own?

ASUSTek COMPUTER INC. holds 93 OUI prefixes in the IEEE registry, of which 3C:7C:3F is one. A device made by ASUSTek COMPUTER INC. could carry a MAC address from any of them.

ASUSTek COMPUTER INC.

MAC address prefix 3C:7C:3F is registered to ASUSTek COMPUTER INC. in the IEEE OUI registry. Any device whose MAC address begins with 3C:7C:3F has a network interface built by ASUSTek COMPUTER 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 3C:7C:3F:00:00:00 to 3C:7C:3F:FF:FF:FF.

OUI prefix: 3C:7C:3F
Hyphen form: 3C-7C-3F
MAC range: 3C:7C:3F:00:00:00 – 3C:7C:3F:FF:FF:FF
Addresses in block: 16,777,216
Organization: ASUSTek COMPUTER INC.
Address: 15,Li-Te Rd., Peitou, Taipei 112, Taiwan Taipei Taiwan TW 112
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 ASUSTek COMPUTER INC.

ASUSTek COMPUTER INC. holds 93 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.

2020-08-05Assigned to "ASUSTek COMPUTER INC."
archived source →
2026-07-17Assigned to "ASUSTek COMPUTER INC."

Nearby in the registry

The prefixes assigned immediately before and after 3C:7C:3F:

FAQ

Which company owns MAC address prefix 3C:7C:3F?: MAC address prefix 3C:7C:3F is registered to ASUSTek COMPUTER INC. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 3C:7C:3F has a network interface built by ASUSTek COMPUTER INC..
What is the OUI 3C:7C:3F?: 3C:7C:3F is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to ASUSTek COMPUTER INC.. It covers every address from 3C:7C:3F:00:00:00 to 3C:7C:3F:FF:FF:FF, or 16,777,216 addresses in total. It is also written 3C-7C-3F.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 3C:7C:3F:00:00:00 that is 3C:7C:3F — 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 ASUSTek COMPUTER INC. located?: ASUSTek COMPUTER INC. is listed at 15,Li-Te Rd., Peitou, Taipei 112, Taiwan Taipei Taiwan TW 112 in the IEEE OUI registry entry for 3C:7C:3F. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does ASUSTek COMPUTER INC. own?: ASUSTek COMPUTER INC. holds 93 OUI prefixes in the IEEE registry, of which 3C:7C:3F is one. A device made by ASUSTek COMPUTER INC. could carry a MAC address from any of them.