Which company owns MAC address prefix C0:81:70?

MAC address prefix C0:81:70 is registered to Effigis GeoSolutions in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C0:81:70 has a network interface built by Effigis GeoSolutions.

What is the OUI C0:81:70?

C0:81:70 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Effigis GeoSolutions. It covers every address from C0:81:70:00:00:00 to C0:81:70:FF:FF:FF, or 16,777,216 addresses in total. It is also written C0-81-70.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in C0:81:70:00:00:00 that is C0:81:70 — 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 Effigis GeoSolutions located?

Effigis GeoSolutions is listed at 4101, rue Molson Montreal Quebec CA H1Y3L1 in the IEEE OUI registry entry for C0:81:70. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Effigis GeoSolutions

MAC address prefix C0:81:70 is registered to Effigis GeoSolutions in the IEEE OUI registry. Any device whose MAC address begins with C0:81:70 has a network interface built by Effigis GeoSolutions. 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 C0:81:70:00:00:00 to C0:81:70:FF:FF:FF.

OUI prefix: C0:81:70
Hyphen form: C0-81-70
MAC range: C0:81:70:00:00:00 – C0:81:70:FF:FF:FF
Addresses in block: 16,777,216
Organization: Effigis GeoSolutions
Address: 4101, rue Molson Montreal Quebec CA H1Y3L1
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 "Effigis GeoSolutions"
archived source →
2026-07-17Assigned to "Effigis GeoSolutions"

Nearby in the registry

The prefixes assigned immediately before and after C0:81:70:

FAQ

Which company owns MAC address prefix C0:81:70?: MAC address prefix C0:81:70 is registered to Effigis GeoSolutions in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with C0:81:70 has a network interface built by Effigis GeoSolutions.
What is the OUI C0:81:70?: C0:81:70 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Effigis GeoSolutions. It covers every address from C0:81:70:00:00:00 to C0:81:70:FF:FF:FF, or 16,777,216 addresses in total. It is also written C0-81-70.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in C0:81:70:00:00:00 that is C0:81:70 — 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 Effigis GeoSolutions located?: Effigis GeoSolutions is listed at 4101, rue Molson Montreal Quebec CA H1Y3L1 in the IEEE OUI registry entry for C0:81:70. This is the address the organization registered with the IEEE, which may differ from its current operating address.