Which company owns MAC address prefix B4:A9:4F?

MAC address prefix B4:A9:4F is registered to MERCURY CORPORATION in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with B4:A9:4F has a network interface built by MERCURY CORPORATION.

What is the OUI B4:A9:4F?

B4:A9:4F is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to MERCURY CORPORATION. It covers every address from B4:A9:4F:00:00:00 to B4:A9:4F:FF:FF:FF, or 16,777,216 addresses in total. It is also written B4-A9-4F.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in B4:A9:4F:00:00:00 that is B4:A9:4F — 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 MERCURY CORPORATION located?

MERCURY CORPORATION is listed at 90, Gajaeul-ro, Seo-gu INCHEON KR 22830 in the IEEE OUI registry entry for B4:A9:4F. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does MERCURY CORPORATION own?

MERCURY CORPORATION holds 6 OUI prefixes in the IEEE registry, of which B4:A9:4F is one. A device made by MERCURY CORPORATION could carry a MAC address from any of them.

MERCURY CORPORATION

MAC address prefix B4:A9:4F is registered to MERCURY CORPORATION in the IEEE OUI registry. Any device whose MAC address begins with B4:A9:4F has a network interface built by MERCURY CORPORATION. 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 B4:A9:4F:00:00:00 to B4:A9:4F:FF:FF:FF.

OUI prefix: B4:A9:4F
Hyphen form: B4-A9-4F
MAC range: B4:A9:4F:00:00:00 – B4:A9:4F:FF:FF:FF
Addresses in block: 16,777,216
Organization: MERCURY CORPORATION
Address: 90, Gajaeul-ro, Seo-gu INCHEON KR 22830
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 MERCURY CORPORATION

MERCURY CORPORATION holds 6 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.

2018-12-21Assigned to "MERCURY CORPORATION"
archived source →
2026-07-17Assigned to "MERCURY CORPORATION"

Nearby in the registry

The prefixes assigned immediately before and after B4:A9:4F:

FAQ

Which company owns MAC address prefix B4:A9:4F?: MAC address prefix B4:A9:4F is registered to MERCURY CORPORATION in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with B4:A9:4F has a network interface built by MERCURY CORPORATION.
What is the OUI B4:A9:4F?: B4:A9:4F is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to MERCURY CORPORATION. It covers every address from B4:A9:4F:00:00:00 to B4:A9:4F:FF:FF:FF, or 16,777,216 addresses in total. It is also written B4-A9-4F.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in B4:A9:4F:00:00:00 that is B4:A9:4F — 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 MERCURY CORPORATION located?: MERCURY CORPORATION is listed at 90, Gajaeul-ro, Seo-gu INCHEON KR 22830 in the IEEE OUI registry entry for B4:A9:4F. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does MERCURY CORPORATION own?: MERCURY CORPORATION holds 6 OUI prefixes in the IEEE registry, of which B4:A9:4F is one. A device made by MERCURY CORPORATION could carry a MAC address from any of them.