Which company owns MAC address prefix C8:16:A5?

MAC address prefix C8:16:A5 is registered to Masimo Corporation in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C8:16:A5 has a network interface built by Masimo Corporation.

What is the OUI C8:16:A5?

C8:16:A5 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Masimo Corporation. It covers every address from C8:16:A5:00:00:00 to C8:16:A5:FF:FF:FF, or 16,777,216 addresses in total. It is also written C8-16-A5.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in C8:16:A5:00:00:00 that is C8:16:A5 — 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 Masimo Corporation located?

Masimo Corporation is listed at 52 Discovery Irvine CA US 92618 in the IEEE OUI registry entry for C8:16:A5. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does Masimo Corporation own?

Masimo Corporation holds 6 OUI prefixes in the IEEE registry, of which C8:16:A5 is one. A device made by Masimo Corporation could carry a MAC address from any of them.

Masimo Corporation

MAC address prefix C8:16:A5 is registered to Masimo Corporation in the IEEE OUI registry. Any device whose MAC address begins with C8:16:A5 has a network interface built by Masimo 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 C8:16:A5:00:00:00 to C8:16:A5:FF:FF:FF.

OUI prefix: C8:16:A5
Hyphen form: C8-16-A5
MAC range: C8:16:A5:00:00:00 – C8:16:A5:FF:FF:FF
Addresses in block: 16,777,216
Organization: Masimo Corporation
Address: 52 Discovery Irvine CA US 92618
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 Masimo Corporation

Masimo 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.

2017-09-08Assigned to "Masimo Corporation"
archived source →
2026-07-17Assigned to "Masimo Corporation"

Nearby in the registry

The prefixes assigned immediately before and after C8:16:A5:

FAQ

Which company owns MAC address prefix C8:16:A5?: MAC address prefix C8:16:A5 is registered to Masimo Corporation in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C8:16:A5 has a network interface built by Masimo Corporation.
What is the OUI C8:16:A5?: C8:16:A5 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Masimo Corporation. It covers every address from C8:16:A5:00:00:00 to C8:16:A5:FF:FF:FF, or 16,777,216 addresses in total. It is also written C8-16-A5.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in C8:16:A5:00:00:00 that is C8:16:A5 — 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 Masimo Corporation located?: Masimo Corporation is listed at 52 Discovery Irvine CA US 92618 in the IEEE OUI registry entry for C8:16:A5. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does Masimo Corporation own?: Masimo Corporation holds 6 OUI prefixes in the IEEE registry, of which C8:16:A5 is one. A device made by Masimo Corporation could carry a MAC address from any of them.