Which company owns MAC address prefix 00:50:B1?

MAC address prefix 00:50:B1 is registered to GIDDINGS & LEWIS in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:50:B1 has a network interface built by GIDDINGS & LEWIS.

What is the OUI 00:50:B1?

00:50:B1 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to GIDDINGS & LEWIS. It covers every address from 00:50:B1:00:00:00 to 00:50:B1:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-50-B1.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 00:50:B1:00:00:00 that is 00:50:B1 — 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 GIDDINGS & LEWIS located?

GIDDINGS & LEWIS is listed at 660 S. MILITARY RD. FOND DU LAC WI US 54935 in the IEEE OUI registry entry for 00:50:B1. This is the address the organization registered with the IEEE, which may differ from its current operating address.

GIDDINGS & LEWIS

MAC address prefix 00:50:B1 is registered to GIDDINGS & LEWIS in the IEEE OUI registry. Any device whose MAC address begins with 00:50:B1 has a network interface built by GIDDINGS & LEWIS. 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 00:50:B1:00:00:00 to 00:50:B1:FF:FF:FF.

OUI prefix: 00:50:B1
Hyphen form: 00-50-B1
MAC range: 00:50:B1:00:00:00 – 00:50:B1:FF:FF:FF
Addresses in block: 16,777,216
Organization: GIDDINGS & LEWIS
Address: 660 S. MILITARY RD. FOND DU LAC WI US 54935
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 "GIDDINGS & LEWIS"
archived source →
2026-07-17Assigned to "GIDDINGS & LEWIS"

Nearby in the registry

The prefixes assigned immediately before and after 00:50:B1:

FAQ

Which company owns MAC address prefix 00:50:B1?: MAC address prefix 00:50:B1 is registered to GIDDINGS & LEWIS in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 00:50:B1 has a network interface built by GIDDINGS & LEWIS.
What is the OUI 00:50:B1?: 00:50:B1 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to GIDDINGS & LEWIS. It covers every address from 00:50:B1:00:00:00 to 00:50:B1:FF:FF:FF, or 16,777,216 addresses in total. It is also written 00-50-B1.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 00:50:B1:00:00:00 that is 00:50:B1 — 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 GIDDINGS & LEWIS located?: GIDDINGS & LEWIS is listed at 660 S. MILITARY RD. FOND DU LAC WI US 54935 in the IEEE OUI registry entry for 00:50:B1. This is the address the organization registered with the IEEE, which may differ from its current operating address.