Which company owns MAC address prefix 5C:B5:59?

MAC address prefix 5C:B5:59 is registered to CNEX Labs in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 5C:B5:59 has a network interface built by CNEX Labs.

What is the OUI 5C:B5:59?

5C:B5:59 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to CNEX Labs. It covers every address from 5C:B5:59:00:00:00 to 5C:B5:59:FF:FF:FF, or 16,777,216 addresses in total. It is also written 5C-B5-59.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 5C:B5:59:00:00:00 that is 5C:B5:59 — 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 CNEX Labs located?

CNEX Labs is listed at 2880 Stevens Creek Blvd San Jose CA US 95128 in the IEEE OUI registry entry for 5C:B5:59. This is the address the organization registered with the IEEE, which may differ from its current operating address.

CNEX Labs

MAC address prefix 5C:B5:59 is registered to CNEX Labs in the IEEE OUI registry. Any device whose MAC address begins with 5C:B5:59 has a network interface built by CNEX Labs. 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 5C:B5:59:00:00:00 to 5C:B5:59:FF:FF:FF.

OUI prefix: 5C:B5:59
Hyphen form: 5C-B5-59
MAC range: 5C:B5:59:00:00:00 – 5C:B5:59:FF:FF:FF
Addresses in block: 16,777,216
Organization: CNEX Labs
Address: 2880 Stevens Creek Blvd San Jose CA US 95128
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 "CNEX Labs"
archived source →
2026-07-17Assigned to "CNEX Labs"

Nearby in the registry

The prefixes assigned immediately before and after 5C:B5:59:

FAQ

Which company owns MAC address prefix 5C:B5:59?: MAC address prefix 5C:B5:59 is registered to CNEX Labs in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 5C:B5:59 has a network interface built by CNEX Labs.
What is the OUI 5C:B5:59?: 5C:B5:59 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to CNEX Labs. It covers every address from 5C:B5:59:00:00:00 to 5C:B5:59:FF:FF:FF, or 16,777,216 addresses in total. It is also written 5C-B5-59.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 5C:B5:59:00:00:00 that is 5C:B5:59 — 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 CNEX Labs located?: CNEX Labs is listed at 2880 Stevens Creek Blvd San Jose CA US 95128 in the IEEE OUI registry entry for 5C:B5:59. This is the address the organization registered with the IEEE, which may differ from its current operating address.