Which company owns MAC address prefix CC:C5:EF?

MAC address prefix CC:C5:EF is registered to Co-Comm Servicios Telecomunicaciones S.L. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with CC:C5:EF has a network interface built by Co-Comm Servicios Telecomunicaciones S.L..

What is the OUI CC:C5:EF?

CC:C5:EF is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Co-Comm Servicios Telecomunicaciones S.L.. It covers every address from CC:C5:EF:00:00:00 to CC:C5:EF:FF:FF:FF, or 16,777,216 addresses in total. It is also written CC-C5-EF.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in CC:C5:EF:00:00:00 that is CC:C5: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 Co-Comm Servicios Telecomunicaciones S.L. located?

Co-Comm Servicios Telecomunicaciones S.L. is listed at Lisboa, 20 Las Rozas Madrid Madrid ES 28232 in the IEEE OUI registry entry for CC:C5:EF. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Co-Comm Servicios Telecomunicaciones S.L.

MAC address prefix CC:C5:EF is registered to Co-Comm Servicios Telecomunicaciones S.L. in the IEEE OUI registry. Any device whose MAC address begins with CC:C5:EF has a network interface built by Co-Comm Servicios Telecomunicaciones S.L.. 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:C5:EF:00:00:00 to CC:C5:EF:FF:FF:FF.

OUI prefix: CC:C5:EF
Hyphen form: CC-C5-EF
MAC range: CC:C5:EF:00:00:00 – CC:C5:EF:FF:FF:FF
Addresses in block: 16,777,216
Organization: Co-Comm Servicios Telecomunicaciones S.L.
Address: Lisboa, 20 Las Rozas Madrid Madrid ES 28232
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 "Co-Comm Servicios Telecomunicaciones S.L."
archived source →
2026-07-17Assigned to "Co-Comm Servicios Telecomunicaciones S.L."

Nearby in the registry

The prefixes assigned immediately before and after CC:C5:EF:

FAQ

Which company owns MAC address prefix CC:C5:EF?: MAC address prefix CC:C5:EF is registered to Co-Comm Servicios Telecomunicaciones S.L. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with CC:C5:EF has a network interface built by Co-Comm Servicios Telecomunicaciones S.L..
What is the OUI CC:C5:EF?: CC:C5:EF is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Co-Comm Servicios Telecomunicaciones S.L.. It covers every address from CC:C5:EF:00:00:00 to CC:C5:EF:FF:FF:FF, or 16,777,216 addresses in total. It is also written CC-C5-EF.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in CC:C5:EF:00:00:00 that is CC:C5: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 Co-Comm Servicios Telecomunicaciones S.L. located?: Co-Comm Servicios Telecomunicaciones S.L. is listed at Lisboa, 20 Las Rozas Madrid Madrid ES 28232 in the IEEE OUI registry entry for CC:C5:EF. This is the address the organization registered with the IEEE, which may differ from its current operating address.