Which company owns MAC address prefix CC:6D:EF?

MAC address prefix CC:6D:EF is registered to TJK Tietolaite Oy in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with CC:6D:EF has a network interface built by TJK Tietolaite Oy.

What is the OUI CC:6D:EF?

CC:6D:EF is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to TJK Tietolaite Oy. It covers every address from CC:6D:EF:00:00:00 to CC:6D:EF:FF:FF:FF, or 16,777,216 addresses in total. It is also written CC-6D-EF.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in CC:6D:EF:00:00:00 that is CC:6D:EF — 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 TJK Tietolaite Oy located?

TJK Tietolaite Oy is listed at PL 443 Vaasa FI 65101 in the IEEE OUI registry entry for CC:6D:EF. This is the address the organization registered with the IEEE, which may differ from its current operating address.

TJK Tietolaite Oy

MAC address prefix CC:6D:EF is registered to TJK Tietolaite Oy in the IEEE OUI registry. Any device whose MAC address begins with CC:6D:EF has a network interface built by TJK Tietolaite Oy. 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 CC:6D:EF:00:00:00 to CC:6D:EF:FF:FF:FF.

OUI prefix: CC:6D:EF
Hyphen form: CC-6D-EF
MAC range: CC:6D:EF:00:00:00 – CC:6D:EF:FF:FF:FF
Addresses in block: 16,777,216
Organization: TJK Tietolaite Oy
Address: PL 443 Vaasa FI 65101
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 "TJK Tietolaite Oy"
archived source →
2026-07-17Assigned to "TJK Tietolaite Oy"

Nearby in the registry

The prefixes assigned immediately before and after CC:6D:EF:

FAQ

Which company owns MAC address prefix CC:6D:EF?: MAC address prefix CC:6D:EF is registered to TJK Tietolaite Oy in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with CC:6D:EF has a network interface built by TJK Tietolaite Oy.
What is the OUI CC:6D:EF?: CC:6D:EF is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to TJK Tietolaite Oy. It covers every address from CC:6D:EF:00:00:00 to CC:6D:EF:FF:FF:FF, or 16,777,216 addresses in total. It is also written CC-6D-EF.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in CC:6D:EF:00:00:00 that is CC:6D:EF — 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 TJK Tietolaite Oy located?: TJK Tietolaite Oy is listed at PL 443 Vaasa FI 65101 in the IEEE OUI registry entry for CC:6D:EF. This is the address the organization registered with the IEEE, which may differ from its current operating address.