Which company owns MAC address prefix A4:0E:2B?

MAC address prefix A4:0E:2B is registered to Facebook Inc in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with A4:0E:2B has a network interface built by Facebook Inc.

What is the OUI A4:0E:2B?

A4:0E:2B is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Facebook Inc. It covers every address from A4:0E:2B:00:00:00 to A4:0E:2B:FF:FF:FF, or 16,777,216 addresses in total. It is also written A4-0E-2B.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in A4:0E:2B:00:00:00 that is A4:0E:2B — 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 Facebook Inc located?

Facebook Inc is listed at 1 Hacker Way Menlo Park CA US 94025 in the IEEE OUI registry entry for A4:0E:2B. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does Facebook Inc own?

Facebook Inc holds 2 OUI prefixes in the IEEE registry, of which A4:0E:2B is one. A device made by Facebook Inc could carry a MAC address from any of them.

Facebook Inc

MAC address prefix A4:0E:2B is registered to Facebook Inc in the IEEE OUI registry. Any device whose MAC address begins with A4:0E:2B has a network interface built by Facebook Inc. 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 A4:0E:2B:00:00:00 to A4:0E:2B:FF:FF:FF.

OUI prefix: A4:0E:2B
Hyphen form: A4-0E-2B
MAC range: A4:0E:2B:00:00:00 – A4:0E:2B:FF:FF:FF
Addresses in block: 16,777,216
Organization: Facebook Inc
Address: 1 Hacker Way Menlo Park CA US 94025
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 Facebook Inc

Facebook Inc holds 2 OUI prefixes in total. A device with this exact prefix could just as well carry any of these:

48:57:DD

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 "Facebook Inc"
archived source →
2026-07-17Assigned to "Facebook Inc"

Nearby in the registry

The prefixes assigned immediately before and after A4:0E:2B:

FAQ

Which company owns MAC address prefix A4:0E:2B?: MAC address prefix A4:0E:2B is registered to Facebook Inc in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with A4:0E:2B has a network interface built by Facebook Inc.
What is the OUI A4:0E:2B?: A4:0E:2B is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Facebook Inc. It covers every address from A4:0E:2B:00:00:00 to A4:0E:2B:FF:FF:FF, or 16,777,216 addresses in total. It is also written A4-0E-2B.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in A4:0E:2B:00:00:00 that is A4:0E:2B — 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 Facebook Inc located?: Facebook Inc is listed at 1 Hacker Way Menlo Park CA US 94025 in the IEEE OUI registry entry for A4:0E:2B. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does Facebook Inc own?: Facebook Inc holds 2 OUI prefixes in the IEEE registry, of which A4:0E:2B is one. A device made by Facebook Inc could carry a MAC address from any of them.