Which company owns MAC address prefix B8:91:C9?

MAC address prefix B8:91:C9 is registered to Handreamnet in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with B8:91:C9 has a network interface built by Handreamnet.

What is the OUI B8:91:C9?

B8:91:C9 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Handreamnet. It covers every address from B8:91:C9:00:00:00 to B8:91:C9:FF:FF:FF, or 16,777,216 addresses in total. It is also written B8-91-C9.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in B8:91:C9:00:00:00 that is B8:91:C9 — 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 Handreamnet located?

Handreamnet is listed at #1203 Ace High-end Tower II, 61, Digital-ro 26-gil, Guro-Gu Seoul KR 08389 in the IEEE OUI registry entry for B8:91:C9. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does Handreamnet own?

Handreamnet holds 3 OUI prefixes in the IEEE registry, of which B8:91:C9 is one. A device made by Handreamnet could carry a MAC address from any of them.

Handreamnet

MAC address prefix B8:91:C9 is registered to Handreamnet in the IEEE OUI registry. Any device whose MAC address begins with B8:91:C9 has a network interface built by Handreamnet. 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 B8:91:C9:00:00:00 to B8:91:C9:FF:FF:FF.

OUI prefix: B8:91:C9
Hyphen form: B8-91-C9
MAC range: B8:91:C9:00:00:00 – B8:91:C9:FF:FF:FF
Addresses in block: 16,777,216
Organization: Handreamnet
Address: #1203 Ace High-end Tower II, 61, Digital-ro 26-gil, Guro-Gu Seoul KR 08389
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 Handreamnet

Handreamnet holds 3 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.

2019-07-04Assigned to "Handreamnet"
archived source →
2026-07-17Assigned to "Handreamnet"

Nearby in the registry

The prefixes assigned immediately before and after B8:91:C9:

FAQ

Which company owns MAC address prefix B8:91:C9?: MAC address prefix B8:91:C9 is registered to Handreamnet in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with B8:91:C9 has a network interface built by Handreamnet.
What is the OUI B8:91:C9?: B8:91:C9 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Handreamnet. It covers every address from B8:91:C9:00:00:00 to B8:91:C9:FF:FF:FF, or 16,777,216 addresses in total. It is also written B8-91-C9.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in B8:91:C9:00:00:00 that is B8:91:C9 — 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 Handreamnet located?: Handreamnet is listed at #1203 Ace High-end Tower II, 61, Digital-ro 26-gil, Guro-Gu Seoul KR 08389 in the IEEE OUI registry entry for B8:91:C9. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does Handreamnet own?: Handreamnet holds 3 OUI prefixes in the IEEE registry, of which B8:91:C9 is one. A device made by Handreamnet could carry a MAC address from any of them.