Which company owns MAC address prefix 58:78:03?

MAC address prefix 58:78:03 is registered to Unitek A/S in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 58:78:03 has a network interface built by Unitek A/S.

What is the OUI 58:78:03?

58:78:03 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Unitek A/S. It covers every address from 58:78:03:00:00:00 to 58:78:03:FF:FF:FF, or 16,777,216 addresses in total. It is also written 58-78-03.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 58:78:03:00:00:00 that is 58:78:03 — 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 Unitek A/S located?

Unitek A/S is listed at Vaevervej 5 Viborg DK 8800 in the IEEE OUI registry entry for 58:78:03. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Unitek A/S

MAC address prefix 58:78:03 is registered to Unitek A/S in the IEEE OUI registry. Any device whose MAC address begins with 58:78:03 has a network interface built by Unitek A/S. 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 58:78:03:00:00:00 to 58:78:03:FF:FF:FF.

OUI prefix: 58:78:03
Hyphen form: 58-78-03
MAC range: 58:78:03:00:00:00 – 58:78:03:FF:FF:FF
Addresses in block: 16,777,216
Organization: Unitek A/S
Address: Vaevervej 5 Viborg DK 8800
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 (1)

The IEEE registry publishes current state only — this is the change record we've kept since we started tracking it daily.

2026-10-02Assigned to "Unitek A/S"

Nearby in the registry

The prefixes assigned immediately before and after 58:78:03:

FAQ

Which company owns MAC address prefix 58:78:03?: MAC address prefix 58:78:03 is registered to Unitek A/S in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 58:78:03 has a network interface built by Unitek A/S.
What is the OUI 58:78:03?: 58:78:03 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Unitek A/S. It covers every address from 58:78:03:00:00:00 to 58:78:03:FF:FF:FF, or 16,777,216 addresses in total. It is also written 58-78-03.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 58:78:03:00:00:00 that is 58:78:03 — 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 Unitek A/S located?: Unitek A/S is listed at Vaevervej 5 Viborg DK 8800 in the IEEE OUI registry entry for 58:78:03. This is the address the organization registered with the IEEE, which may differ from its current operating address.