Which company owns MAC address prefix 00:23:78?

MAC address prefix 00:23:78 is registered to GN Netcom A/S in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:23:78 has a network interface built by GN Netcom A/S.

What is the OUI 00:23:78?

00:23:78 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to GN Netcom A/S. It covers every address from 00:23:78:00:00:00 to 00:23:78:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-23-78.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 00:23:78:00:00:00 that is 00:23:78 — 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 GN Netcom A/S located?

GN Netcom A/S is listed at Lautrupbjerg 7 Ballerup DK DK - 2750 in the IEEE OUI registry entry for 00:23:78. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does GN Netcom A/S own?

GN Netcom A/S holds 8 OUI prefixes in the IEEE registry, of which 00:23:78 is one. A device made by GN Netcom A/S could carry a MAC address from any of them.

GN Netcom A/S

MAC address prefix 00:23:78 is registered to GN Netcom A/S in the IEEE OUI registry. Any device whose MAC address begins with 00:23:78 has a network interface built by GN Netcom A/S. 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 00:23:78:00:00:00 to 00:23:78:FF:FF:FF.

OUI prefix: 00:23:78
Hyphen form: 00-23-78
MAC range: 00:23:78:00:00:00 – 00:23:78:FF:FF:FF
Addresses in block: 16,777,216
Organization: GN Netcom A/S
Address: Lautrupbjerg 7 Ballerup DK DK - 2750
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 GN Netcom A/S

GN Netcom A/S holds 8 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 "GN Netcom A/S"
archived source →
2026-07-17Assigned to "GN Netcom A/S"

Nearby in the registry

The prefixes assigned immediately before and after 00:23:78:

FAQ

Which company owns MAC address prefix 00:23:78?: MAC address prefix 00:23:78 is registered to GN Netcom A/S in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:23:78 has a network interface built by GN Netcom A/S.
What is the OUI 00:23:78?: 00:23:78 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to GN Netcom A/S. It covers every address from 00:23:78:00:00:00 to 00:23:78:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-23-78.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 00:23:78:00:00:00 that is 00:23:78 — 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 GN Netcom A/S located?: GN Netcom A/S is listed at Lautrupbjerg 7 Ballerup DK DK - 2750 in the IEEE OUI registry entry for 00:23:78. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does GN Netcom A/S own?: GN Netcom A/S holds 8 OUI prefixes in the IEEE registry, of which 00:23:78 is one. A device made by GN Netcom A/S could carry a MAC address from any of them.