Which company owns MAC address prefix 00:0F:66?

MAC address prefix 00:0F:66 is registered to Cisco-Linksys, LLC in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:0F:66 has a network interface built by Cisco-Linksys, LLC.

What is the OUI 00:0F:66?

00:0F:66 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Cisco-Linksys, LLC. It covers every address from 00:0F:66:00:00:00 to 00:0F:66:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-0F-66.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 00:0F:66:00:00:00 that is 00:0F:66 — 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 Cisco-Linksys, LLC located?

Cisco-Linksys, LLC is listed at 121 Theory Dr. Irvine CA US 92612 in the IEEE OUI registry entry for 00:0F:66. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does Cisco-Linksys, LLC own?

Cisco-Linksys, LLC holds 25 OUI prefixes in the IEEE registry, of which 00:0F:66 is one. A device made by Cisco-Linksys, LLC could carry a MAC address from any of them.

Cisco-Linksys, LLC

MAC address prefix 00:0F:66 is registered to Cisco-Linksys, LLC in the IEEE OUI registry. Any device whose MAC address begins with 00:0F:66 has a network interface built by Cisco-Linksys, LLC. 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 00:0F:66:00:00:00 to 00:0F:66:FF:FF:FF.

OUI prefix: 00:0F:66
Hyphen form: 00-0F-66
MAC range: 00:0F:66:00:00:00 – 00:0F:66:FF:FF:FF
Addresses in block: 16,777,216
Organization: Cisco-Linksys, LLC
Address: 121 Theory Dr. Irvine CA US 92612
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 Cisco-Linksys, LLC

Cisco-Linksys, LLC holds 25 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.

2016-07-29Assigned to "Cisco-Linksys, LLC"
archived source →
2026-07-17Assigned to "Cisco-Linksys, LLC"

Nearby in the registry

The prefixes assigned immediately before and after 00:0F:66:

FAQ

Which company owns MAC address prefix 00:0F:66?: MAC address prefix 00:0F:66 is registered to Cisco-Linksys, LLC in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:0F:66 has a network interface built by Cisco-Linksys, LLC.
What is the OUI 00:0F:66?: 00:0F:66 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Cisco-Linksys, LLC. It covers every address from 00:0F:66:00:00:00 to 00:0F:66:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-0F-66.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 00:0F:66:00:00:00 that is 00:0F:66 — 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 Cisco-Linksys, LLC located?: Cisco-Linksys, LLC is listed at 121 Theory Dr. Irvine CA US 92612 in the IEEE OUI registry entry for 00:0F:66. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does Cisco-Linksys, LLC own?: Cisco-Linksys, LLC holds 25 OUI prefixes in the IEEE registry, of which 00:0F:66 is one. A device made by Cisco-Linksys, LLC could carry a MAC address from any of them.