Which company owns MAC address prefix E0:A5:09?

MAC address prefix E0:A5:09 is registered to Bitmain Technologies Inc in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with E0:A5:09 has a network interface built by Bitmain Technologies Inc.

What is the OUI E0:A5:09?

E0:A5:09 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Bitmain Technologies Inc. It covers every address from E0:A5:09:00:00:00 to E0:A5:09:FF:FF:FF, or 16,777,216 addresses in total. It is also written E0-A5-09.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in E0:A5:09:00:00:00 that is E0:A5:09 — 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 Bitmain Technologies Inc located?

Bitmain Technologies Inc is listed at Building 25, North Olympic Science & Technology Park, Baosheng South Road, Haidian District, Beijing, China Beijing BEIJING CN CHINA in the IEEE OUI registry entry for E0:A5:09. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Bitmain Technologies Inc

MAC address prefix E0:A5:09 is registered to Bitmain Technologies Inc in the IEEE OUI registry. Any device whose MAC address begins with E0:A5:09 has a network interface built by Bitmain Technologies 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 E0:A5:09:00:00:00 to E0:A5:09:FF:FF:FF.

OUI prefix: E0:A5:09
Hyphen form: E0-A5-09
MAC range: E0:A5:09:00:00:00 – E0:A5:09:FF:FF:FF
Addresses in block: 16,777,216
Organization: Bitmain Technologies Inc
Address: Building 25, North Olympic Science & Technology Park, Baosheng South Road, Haidian District, Beijing, China Beijing BEIJING CN CHINA
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.

2018-12-21Assigned to "Bitmain Technologies Inc"
archived source →
2026-07-17Assigned to "Bitmain Technologies Inc"

Nearby in the registry

The prefixes assigned immediately before and after E0:A5:09:

FAQ

Which company owns MAC address prefix E0:A5:09?: MAC address prefix E0:A5:09 is registered to Bitmain Technologies Inc in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with E0:A5:09 has a network interface built by Bitmain Technologies Inc.
What is the OUI E0:A5:09?: E0:A5:09 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Bitmain Technologies Inc. It covers every address from E0:A5:09:00:00:00 to E0:A5:09:FF:FF:FF, or 16,777,216 addresses in total. It is also written E0-A5-09.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in E0:A5:09:00:00:00 that is E0:A5:09 — 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 Bitmain Technologies Inc located?: Bitmain Technologies Inc is listed at Building 25, North Olympic Science & Technology Park, Baosheng South Road, Haidian District, Beijing, China Beijing BEIJING CN CHINA in the IEEE OUI registry entry for E0:A5:09. This is the address the organization registered with the IEEE, which may differ from its current operating address.