Which company owns MAC address prefix 00:90:45?

MAC address prefix 00:90:45 is registered to Marconi Communications in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:90:45 has a network interface built by Marconi Communications.

What is the OUI 00:90:45?

00:90:45 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Marconi Communications. It covers every address from 00:90:45:00:00:00 to 00:90:45:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-90-45.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 00:90:45:00:00:00 that is 00:90:45 — 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 Marconi Communications located?

Marconi Communications is listed at 1000 Fore Drive Warrendale PA US 15086-7502 in the IEEE OUI registry entry for 00:90:45. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does Marconi Communications own?

Marconi Communications holds 3 OUI prefixes in the IEEE registry, of which 00:90:45 is one. A device made by Marconi Communications could carry a MAC address from any of them.

Marconi Communications

MAC address prefix 00:90:45 is registered to Marconi Communications in the IEEE OUI registry. Any device whose MAC address begins with 00:90:45 has a network interface built by Marconi Communications. 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 00:90:45:00:00:00 to 00:90:45:FF:FF:FF.

OUI prefix: 00:90:45
Hyphen form: 00-90-45
MAC range: 00:90:45:00:00:00 – 00:90:45:FF:FF:FF
Addresses in block: 16,777,216
Organization: Marconi Communications
Address: 1000 Fore Drive Warrendale PA US 15086-7502
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 Marconi Communications

Marconi Communications holds 3 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 "Marconi Communications"
archived source →
2026-07-17Assigned to "Marconi Communications"

Nearby in the registry

The prefixes assigned immediately before and after 00:90:45:

FAQ

Which company owns MAC address prefix 00:90:45?: MAC address prefix 00:90:45 is registered to Marconi Communications in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:90:45 has a network interface built by Marconi Communications.
What is the OUI 00:90:45?: 00:90:45 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Marconi Communications. It covers every address from 00:90:45:00:00:00 to 00:90:45:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-90-45.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 00:90:45:00:00:00 that is 00:90:45 — 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 Marconi Communications located?: Marconi Communications is listed at 1000 Fore Drive Warrendale PA US 15086-7502 in the IEEE OUI registry entry for 00:90:45. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does Marconi Communications own?: Marconi Communications holds 3 OUI prefixes in the IEEE registry, of which 00:90:45 is one. A device made by Marconi Communications could carry a MAC address from any of them.