Which company owns MAC address prefix 58:9C:FC?

MAC address prefix 58:9C:FC is registered to FreeBSD Foundation in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 58:9C:FC has a network interface built by FreeBSD Foundation.

What is the OUI 58:9C:FC?

58:9C:FC is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to FreeBSD Foundation. It covers every address from 58:9C:FC:00:00:00 to 58:9C:FC:FF:FF:FF, or 16,777,216 addresses in total. It is also written 58-9C-FC.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 58:9C:FC:00:00:00 that is 58:9C:FC — 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 FreeBSD Foundation located?

FreeBSD Foundation is listed at P.O. Box 20247 Boulder CO US 80308-3247 in the IEEE OUI registry entry for 58:9C:FC. This is the address the organization registered with the IEEE, which may differ from its current operating address.

FreeBSD Foundation

MAC address prefix 58:9C:FC is registered to FreeBSD Foundation in the IEEE OUI registry. Any device whose MAC address begins with 58:9C:FC has a network interface built by FreeBSD Foundation. 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 58:9C:FC:00:00:00 to 58:9C:FC:FF:FF:FF.

OUI prefix: 58:9C:FC
Hyphen form: 58-9C-FC
MAC range: 58:9C:FC:00:00:00 – 58:9C:FC:FF:FF:FF
Addresses in block: 16,777,216
Organization: FreeBSD Foundation
Address: P.O. Box 20247 Boulder CO US 80308-3247
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 "FreeBSD Foundation"
archived source →
2026-07-17Assigned to "FreeBSD Foundation"

Nearby in the registry

The prefixes assigned immediately before and after 58:9C:FC:

FAQ

Which company owns MAC address prefix 58:9C:FC?: MAC address prefix 58:9C:FC is registered to FreeBSD Foundation in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 58:9C:FC has a network interface built by FreeBSD Foundation.
What is the OUI 58:9C:FC?: 58:9C:FC is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to FreeBSD Foundation. It covers every address from 58:9C:FC:00:00:00 to 58:9C:FC:FF:FF:FF, or 16,777,216 addresses in total. It is also written 58-9C-FC.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 58:9C:FC:00:00:00 that is 58:9C:FC — 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 FreeBSD Foundation located?: FreeBSD Foundation is listed at P.O. Box 20247 Boulder CO US 80308-3247 in the IEEE OUI registry entry for 58:9C:FC. This is the address the organization registered with the IEEE, which may differ from its current operating address.