Which company owns MAC address prefix 4C:5F:D2?

MAC address prefix 4C:5F:D2 is registered to Alcatel-Lucent in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 4C:5F:D2 has a network interface built by Alcatel-Lucent.

What is the OUI 4C:5F:D2?

4C:5F:D2 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Alcatel-Lucent. It covers every address from 4C:5F:D2:00:00:00 to 4C:5F:D2:FF:FF:FF, or 16,777,216 addresses in total. It is also written 4C-5F-D2.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 4C:5F:D2:00:00:00 that is 4C:5F:D2 — 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 Alcatel-Lucent located?

Alcatel-Lucent is listed at 777 East Middlefield Road Mountain View CA US 94043 in the IEEE OUI registry entry for 4C:5F:D2. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does Alcatel-Lucent own?

Alcatel-Lucent holds 8 OUI prefixes in the IEEE registry, of which 4C:5F:D2 is one. A device made by Alcatel-Lucent could carry a MAC address from any of them.

Alcatel-Lucent

MAC address prefix 4C:5F:D2 is registered to Alcatel-Lucent in the IEEE OUI registry. Any device whose MAC address begins with 4C:5F:D2 has a network interface built by Alcatel-Lucent. 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 4C:5F:D2:00:00:00 to 4C:5F:D2:FF:FF:FF.

OUI prefix: 4C:5F:D2
Hyphen form: 4C-5F-D2
MAC range: 4C:5F:D2:00:00:00 – 4C:5F:D2:FF:FF:FF
Addresses in block: 16,777,216
Organization: Alcatel-Lucent
Address: 777 East Middlefield Road Mountain View CA US 94043
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.

Other prefixes from Alcatel-Lucent

Alcatel-Lucent holds 8 OUI prefixes in total. A device with this exact prefix could just as well carry any of these:

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 "Alcatel-Lucent"
archived source →
2026-07-17Assigned to "Alcatel-Lucent"

Nearby in the registry

The prefixes assigned immediately before and after 4C:5F:D2:

FAQ

Which company owns MAC address prefix 4C:5F:D2?: MAC address prefix 4C:5F:D2 is registered to Alcatel-Lucent in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 4C:5F:D2 has a network interface built by Alcatel-Lucent.
What is the OUI 4C:5F:D2?: 4C:5F:D2 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Alcatel-Lucent. It covers every address from 4C:5F:D2:00:00:00 to 4C:5F:D2:FF:FF:FF, or 16,777,216 addresses in total. It is also written 4C-5F-D2.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 4C:5F:D2:00:00:00 that is 4C:5F:D2 — 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 Alcatel-Lucent located?: Alcatel-Lucent is listed at 777 East Middlefield Road Mountain View CA US 94043 in the IEEE OUI registry entry for 4C:5F:D2. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does Alcatel-Lucent own?: Alcatel-Lucent holds 8 OUI prefixes in the IEEE registry, of which 4C:5F:D2 is one. A device made by Alcatel-Lucent could carry a MAC address from any of them.