Which company owns MAC address prefix A8:5E:E4?

MAC address prefix A8:5E:E4 is registered to 12Sided Technology, LLC in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with A8:5E:E4 has a network interface built by 12Sided Technology, LLC.

What is the OUI A8:5E:E4?

A8:5E:E4 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to 12Sided Technology, LLC. It covers every address from A8:5E:E4:00:00:00 to A8:5E:E4:FF:FF:FF, or 16,777,216 addresses in total. It is also written A8-5E-E4.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in A8:5E:E4:00:00:00 that is A8:5E:E4 — 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 12Sided Technology, LLC located?

12Sided Technology, LLC is listed at 1 Penn Plaza, 36th Floor New York NY US 10119 in the IEEE OUI registry entry for A8:5E:E4. This is the address the organization registered with the IEEE, which may differ from its current operating address.

12Sided Technology, LLC

MAC address prefix A8:5E:E4 is registered to 12Sided Technology, LLC in the IEEE OUI registry. Any device whose MAC address begins with A8:5E:E4 has a network interface built by 12Sided Technology, LLC. 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 A8:5E:E4:00:00:00 to A8:5E:E4:FF:FF:FF.

OUI prefix: A8:5E:E4
Hyphen form: A8-5E-E4
MAC range: A8:5E:E4:00:00:00 – A8:5E:E4:FF:FF:FF
Addresses in block: 16,777,216
Organization: 12Sided Technology, LLC
Address: 1 Penn Plaza, 36th Floor New York NY US 10119
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 "12Sided Technology, LLC"
archived source →
2026-07-17Assigned to "12Sided Technology, LLC"

Nearby in the registry

The prefixes assigned immediately before and after A8:5E:E4:

FAQ

Which company owns MAC address prefix A8:5E:E4?: MAC address prefix A8:5E:E4 is registered to 12Sided Technology, LLC in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with A8:5E:E4 has a network interface built by 12Sided Technology, LLC.
What is the OUI A8:5E:E4?: A8:5E:E4 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to 12Sided Technology, LLC. It covers every address from A8:5E:E4:00:00:00 to A8:5E:E4:FF:FF:FF, or 16,777,216 addresses in total. It is also written A8-5E-E4.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in A8:5E:E4:00:00:00 that is A8:5E:E4 — 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 12Sided Technology, LLC located?: 12Sided Technology, LLC is listed at 1 Penn Plaza, 36th Floor New York NY US 10119 in the IEEE OUI registry entry for A8:5E:E4. This is the address the organization registered with the IEEE, which may differ from its current operating address.