Which company owns MAC address prefix 84:C3:E8?

MAC address prefix 84:C3:E8 is registered to Vaillant GmbH in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 84:C3:E8 has a network interface built by Vaillant GmbH.

What is the OUI 84:C3:E8?

84:C3:E8 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Vaillant GmbH. It covers every address from 84:C3:E8:00:00:00 to 84:C3:E8:FF:FF:FF, or 16,777,216 addresses in total. It is also written 84-C3-E8.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 84:C3:E8:00:00:00 that is 84:C3:E8 — 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 Vaillant GmbH located?

Vaillant GmbH is listed at Berghauser Straße 40 Remscheid NRW DE D-42859 in the IEEE OUI registry entry for 84:C3:E8. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Vaillant GmbH

MAC address prefix 84:C3:E8 is registered to Vaillant GmbH in the IEEE OUI registry. Any device whose MAC address begins with 84:C3:E8 has a network interface built by Vaillant GmbH. 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 84:C3:E8:00:00:00 to 84:C3:E8:FF:FF:FF.

OUI prefix: 84:C3:E8
Hyphen form: 84-C3-E8
MAC range: 84:C3:E8:00:00:00 – 84:C3:E8:FF:FF:FF
Addresses in block: 16,777,216
Organization: Vaillant GmbH
Address: Berghauser Straße 40 Remscheid NRW DE D-42859
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 "Vaillant GmbH"
archived source →
2026-07-17Assigned to "Vaillant GmbH"

Nearby in the registry

The prefixes assigned immediately before and after 84:C3:E8:

FAQ

Which company owns MAC address prefix 84:C3:E8?: MAC address prefix 84:C3:E8 is registered to Vaillant GmbH in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 84:C3:E8 has a network interface built by Vaillant GmbH.
What is the OUI 84:C3:E8?: 84:C3:E8 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Vaillant GmbH. It covers every address from 84:C3:E8:00:00:00 to 84:C3:E8:FF:FF:FF, or 16,777,216 addresses in total. It is also written 84-C3-E8.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 84:C3:E8:00:00:00 that is 84:C3:E8 — 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 Vaillant GmbH located?: Vaillant GmbH is listed at Berghauser Straße 40 Remscheid NRW DE D-42859 in the IEEE OUI registry entry for 84:C3:E8. This is the address the organization registered with the IEEE, which may differ from its current operating address.