Which company owns MAC address prefix 7C:C6:C4?

MAC address prefix 7C:C6:C4 is registered to Kolff Computer Supplies b.v. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 7C:C6:C4 has a network interface built by Kolff Computer Supplies b.v..

What is the OUI 7C:C6:C4?

7C:C6:C4 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Kolff Computer Supplies b.v.. It covers every address from 7C:C6:C4:00:00:00 to 7C:C6:C4:FF:FF:FF, or 16,777,216 addresses in total. It is also written 7C-C6-C4.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 7C:C6:C4:00:00:00 that is 7C:C6:C4 — 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 Kolff Computer Supplies b.v. located?

Kolff Computer Supplies b.v. is listed at Kuipershaven 22 Dordrecht Zuid-Holland NL 3311 AL in the IEEE OUI registry entry for 7C:C6:C4. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Kolff Computer Supplies b.v.

MAC address prefix 7C:C6:C4 is registered to Kolff Computer Supplies b.v. in the IEEE OUI registry. Any device whose MAC address begins with 7C:C6:C4 has a network interface built by Kolff Computer Supplies b.v.. 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 7C:C6:C4:00:00:00 to 7C:C6:C4:FF:FF:FF.

OUI prefix: 7C:C6:C4
Hyphen form: 7C-C6-C4
MAC range: 7C:C6:C4:00:00:00 – 7C:C6:C4:FF:FF:FF
Addresses in block: 16,777,216
Organization: Kolff Computer Supplies b.v.
Address: Kuipershaven 22 Dordrecht Zuid-Holland NL 3311 AL
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.

2017-09-08Assigned to "Kolff Computer Supplies b.v."
archived source →
2026-07-17Assigned to "Kolff Computer Supplies b.v."

Nearby in the registry

The prefixes assigned immediately before and after 7C:C6:C4:

FAQ

Which company owns MAC address prefix 7C:C6:C4?: MAC address prefix 7C:C6:C4 is registered to Kolff Computer Supplies b.v. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 7C:C6:C4 has a network interface built by Kolff Computer Supplies b.v..
What is the OUI 7C:C6:C4?: 7C:C6:C4 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Kolff Computer Supplies b.v.. It covers every address from 7C:C6:C4:00:00:00 to 7C:C6:C4:FF:FF:FF, or 16,777,216 addresses in total. It is also written 7C-C6-C4.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 7C:C6:C4:00:00:00 that is 7C:C6:C4 — 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 Kolff Computer Supplies b.v. located?: Kolff Computer Supplies b.v. is listed at Kuipershaven 22 Dordrecht Zuid-Holland NL 3311 AL in the IEEE OUI registry entry for 7C:C6:C4. This is the address the organization registered with the IEEE, which may differ from its current operating address.