Which company owns MAC address prefix 18:B5:91?

MAC address prefix 18:B5:91 is registered to I-Storm in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 18:B5:91 has a network interface built by I-Storm.

What is the OUI 18:B5:91?

18:B5:91 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to I-Storm. It covers every address from 18:B5:91:00:00:00 to 18:B5:91:FF:FF:FF, or 16,777,216 addresses in total. It is also written 18-B5-91.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 18:B5:91:00:00:00 that is 18:B5:91 — 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 I-Storm located?

I-Storm is listed at Hogye-dong, Dongan-gu Anyang-si Gyeonggi-do KR 431-080 in the IEEE OUI registry entry for 18:B5:91. This is the address the organization registered with the IEEE, which may differ from its current operating address.

I-Storm

MAC address prefix 18:B5:91 is registered to I-Storm in the IEEE OUI registry. Any device whose MAC address begins with 18:B5:91 has a network interface built by I-Storm. 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 18:B5:91:00:00:00 to 18:B5:91:FF:FF:FF.

OUI prefix: 18:B5:91
Hyphen form: 18-B5-91
MAC range: 18:B5:91:00:00:00 – 18:B5:91:FF:FF:FF
Addresses in block: 16,777,216
Organization: I-Storm
Address: Hogye-dong, Dongan-gu Anyang-si Gyeonggi-do KR 431-080
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 "I-Storm"
archived source →
2026-07-17Assigned to "I-Storm"

Nearby in the registry

The prefixes assigned immediately before and after 18:B5:91:

FAQ

Which company owns MAC address prefix 18:B5:91?: MAC address prefix 18:B5:91 is registered to I-Storm in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 18:B5:91 has a network interface built by I-Storm.
What is the OUI 18:B5:91?: 18:B5:91 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to I-Storm. It covers every address from 18:B5:91:00:00:00 to 18:B5:91:FF:FF:FF, or 16,777,216 addresses in total. It is also written 18-B5-91.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 18:B5:91:00:00:00 that is 18:B5:91 — 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 I-Storm located?: I-Storm is listed at Hogye-dong, Dongan-gu Anyang-si Gyeonggi-do KR 431-080 in the IEEE OUI registry entry for 18:B5:91. This is the address the organization registered with the IEEE, which may differ from its current operating address.