Which company owns MAC address prefix 34:76:C5?

MAC address prefix 34:76:C5 is registered to I-O DATA, INC. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 34:76:C5 has a network interface built by I-O DATA, INC..

What is the OUI 34:76:C5?

34:76:C5 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to I-O DATA, INC.. It covers every address from 34:76:C5:00:00:00 to 34:76:C5:FF:FF:FF, or 16,777,216 addresses in total. It is also written 34-76-C5.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 34:76:C5:00:00:00 that is 34:76:C5 — 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 I-O DATA, INC. located?

I-O DATA, INC. is listed at 3-10, SAKURADA-MACHI KANAZAWA ISHIKAWA JP 920-8512 in the IEEE OUI registry entry for 34:76:C5. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does I-O DATA, INC. own?

I-O DATA, INC. holds 3 OUI prefixes in the IEEE registry, of which 34:76:C5 is one. A device made by I-O DATA, INC. could carry a MAC address from any of them.

I-O DATA, INC.

MAC address prefix 34:76:C5 is registered to I-O DATA, INC. in the IEEE OUI registry. Any device whose MAC address begins with 34:76:C5 has a network interface built by I-O DATA, INC.. 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 34:76:C5:00:00:00 to 34:76:C5:FF:FF:FF.

OUI prefix: 34:76:C5
Hyphen form: 34-76-C5
MAC range: 34:76:C5:00:00:00 – 34:76:C5:FF:FF:FF
Addresses in block: 16,777,216
Organization: I-O DATA, INC.
Address: 3-10, SAKURADA-MACHI KANAZAWA ISHIKAWA JP 920-8512
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 I-O DATA, INC.

I-O DATA, INC. holds 3 OUI prefixes in total. A device with this exact prefix could just as well carry any of these:

Assignment history (3)

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 "I-O DATA DEVICE, INC."
archived source →
2019-07-04Renamed from "I-O DATA DEVICE, INC." to "I-O DATA DEVICE,INC."
archived source →
2026-07-17Assigned to "I-O DATA, INC."

Nearby in the registry

The prefixes assigned immediately before and after 34:76:C5:

FAQ

Which company owns MAC address prefix 34:76:C5?: MAC address prefix 34:76:C5 is registered to I-O DATA, INC. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 34:76:C5 has a network interface built by I-O DATA, INC..
What is the OUI 34:76:C5?: 34:76:C5 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to I-O DATA, INC.. It covers every address from 34:76:C5:00:00:00 to 34:76:C5:FF:FF:FF, or 16,777,216 addresses in total. It is also written 34-76-C5.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 34:76:C5:00:00:00 that is 34:76:C5 — 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 I-O DATA, INC. located?: I-O DATA, INC. is listed at 3-10, SAKURADA-MACHI KANAZAWA ISHIKAWA JP 920-8512 in the IEEE OUI registry entry for 34:76:C5. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does I-O DATA, INC. own?: I-O DATA, INC. holds 3 OUI prefixes in the IEEE registry, of which 34:76:C5 is one. A device made by I-O DATA, INC. could carry a MAC address from any of them.