Which company owns MAC address prefix C4:C9:EC?

MAC address prefix C4:C9:EC is registered to Gugaoo HK Limited in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C4:C9:EC has a network interface built by Gugaoo HK Limited.

What is the OUI C4:C9:EC?

C4:C9:EC is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Gugaoo HK Limited. It covers every address from C4:C9:EC:00:00:00 to C4:C9:EC:FF:FF:FF, or 16,777,216 addresses in total. It is also written C4-C9-EC.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in C4:C9:EC:00:00:00 that is C4:C9:EC — 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 Gugaoo HK Limited located?

Gugaoo HK Limited is listed at Unit 04, 7/F BRIGHT WAY TOWER Kowloon, Hongkong HK in the IEEE OUI registry entry for C4:C9:EC. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Gugaoo HK Limited

MAC address prefix C4:C9:EC is registered to Gugaoo HK Limited in the IEEE OUI registry. Any device whose MAC address begins with C4:C9:EC has a network interface built by Gugaoo HK Limited. 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 C4:C9:EC:00:00:00 to C4:C9:EC:FF:FF:FF.

OUI prefix: C4:C9:EC
Hyphen form: C4-C9-EC
MAC range: C4:C9:EC:00:00:00 – C4:C9:EC:FF:FF:FF
Addresses in block: 16,777,216
Organization: Gugaoo HK Limited
Address: Unit 04, 7/F BRIGHT WAY TOWER Kowloon, Hongkong HK
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 "Gugaoo HK Limited"
archived source →
2026-07-17Assigned to "Gugaoo HK Limited"

Nearby in the registry

The prefixes assigned immediately before and after C4:C9:EC:

FAQ

Which company owns MAC address prefix C4:C9:EC?: MAC address prefix C4:C9:EC is registered to Gugaoo HK Limited in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C4:C9:EC has a network interface built by Gugaoo HK Limited.
What is the OUI C4:C9:EC?: C4:C9:EC is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Gugaoo HK Limited. It covers every address from C4:C9:EC:00:00:00 to C4:C9:EC:FF:FF:FF, or 16,777,216 addresses in total. It is also written C4-C9-EC.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in C4:C9:EC:00:00:00 that is C4:C9:EC — 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 Gugaoo HK Limited located?: Gugaoo HK Limited is listed at Unit 04, 7/F BRIGHT WAY TOWER Kowloon, Hongkong HK in the IEEE OUI registry entry for C4:C9:EC. This is the address the organization registered with the IEEE, which may differ from its current operating address.