Which company owns MAC address prefix FC:AF:AC?

MAC address prefix FC:AF:AC is registered to Socionext Inc. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with FC:AF:AC has a network interface built by Socionext Inc..

What is the OUI FC:AF:AC?

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

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in FC:AF:AC:00:00:00 that is FC:AF:AC — 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 Socionext Inc. located?

Socionext Inc. is listed at 19 Nishikujo-Kasuga-cho Minaki-ku Kyoto JP 601-8413 in the IEEE OUI registry entry for FC:AF:AC. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Socionext Inc.

MAC address prefix FC:AF:AC is registered to Socionext Inc. in the IEEE OUI registry. Any device whose MAC address begins with FC:AF:AC has a network interface built by Socionext 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 FC:AF:AC:00:00:00 to FC:AF:AC:FF:FF:FF.

OUI prefix: FC:AF:AC
Hyphen form: FC-AF-AC
MAC range: FC:AF:AC:00:00:00 – FC:AF:AC:FF:FF:FF
Addresses in block: 16,777,216
Organization: Socionext Inc.
Address: 19 Nishikujo-Kasuga-cho Minaki-ku Kyoto JP 601-8413
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 "Socionext Inc."
archived source →
2026-07-17Assigned to "Socionext Inc."

Nearby in the registry

The prefixes assigned immediately before and after FC:AF:AC:

FAQ

Which company owns MAC address prefix FC:AF:AC?: MAC address prefix FC:AF:AC is registered to Socionext Inc. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with FC:AF:AC has a network interface built by Socionext Inc..
What is the OUI FC:AF:AC?: FC:AF:AC is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Socionext Inc.. It covers every address from FC:AF:AC:00:00:00 to FC:AF:AC:FF:FF:FF, or 16,777,216 addresses in total. It is also written FC-AF-AC.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in FC:AF:AC:00:00:00 that is FC:AF:AC — 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 Socionext Inc. located?: Socionext Inc. is listed at 19 Nishikujo-Kasuga-cho Minaki-ku Kyoto JP 601-8413 in the IEEE OUI registry entry for FC:AF:AC. This is the address the organization registered with the IEEE, which may differ from its current operating address.