Which company owns MAC address prefix 28:F3:58?

MAC address prefix 28:F3:58 is registered to 2C - Trifonov & Co in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 28:F3:58 has a network interface built by 2C - Trifonov & Co.

What is the OUI 28:F3:58?

28:F3:58 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to 2C - Trifonov & Co. It covers every address from 28:F3:58:00:00:00 to 28:F3:58:FF:FF:FF, or 16,777,216 addresses in total. It is also written 28-F3-58.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 28:F3:58:00:00:00 that is 28:F3:58 — 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 2C - Trifonov & Co located?

2C - Trifonov & Co is listed at 133, Tsarigradsko Shose Blvd, BIZ IZOT, Sofia BG 1784 in the IEEE OUI registry entry for 28:F3:58. This is the address the organization registered with the IEEE, which may differ from its current operating address.

2C - Trifonov & Co

MAC address prefix 28:F3:58 is registered to 2C - Trifonov & Co in the IEEE OUI registry. Any device whose MAC address begins with 28:F3:58 has a network interface built by 2C - Trifonov & Co. 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 28:F3:58:00:00:00 to 28:F3:58:FF:FF:FF.

OUI prefix: 28:F3:58
Hyphen form: 28-F3-58
MAC range: 28:F3:58:00:00:00 – 28:F3:58:FF:FF:FF
Addresses in block: 16,777,216
Organization: 2C - Trifonov & Co
Address: 133, Tsarigradsko Shose Blvd, BIZ IZOT, Sofia BG 1784
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 "2C - Trifonov & Co"
archived source →
2026-07-17Assigned to "2C - Trifonov & Co"

Nearby in the registry

The prefixes assigned immediately before and after 28:F3:58:

FAQ

Which company owns MAC address prefix 28:F3:58?: MAC address prefix 28:F3:58 is registered to 2C - Trifonov & Co in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 28:F3:58 has a network interface built by 2C - Trifonov & Co.
What is the OUI 28:F3:58?: 28:F3:58 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to 2C - Trifonov & Co. It covers every address from 28:F3:58:00:00:00 to 28:F3:58:FF:FF:FF, or 16,777,216 addresses in total. It is also written 28-F3-58.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 28:F3:58:00:00:00 that is 28:F3:58 — 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 2C - Trifonov & Co located?: 2C - Trifonov & Co is listed at 133, Tsarigradsko Shose Blvd, BIZ IZOT, Sofia BG 1784 in the IEEE OUI registry entry for 28:F3:58. This is the address the organization registered with the IEEE, which may differ from its current operating address.