Which company owns MAC address prefix 78:CA:5E?

MAC address prefix 78:CA:5E is registered to ELNO in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 78:CA:5E has a network interface built by ELNO.

What is the OUI 78:CA:5E?

78:CA:5E is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to ELNO. It covers every address from 78:CA:5E:00:00:00 to 78:CA:5E:FF:FF:FF, or 16,777,216 addresses in total. It is also written 78-CA-5E.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 78:CA:5E:00:00:00 that is 78:CA:5E — 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 ELNO located?

ELNO is listed at 43 rue Michel Carré Argenteuil - US F95102 in the IEEE OUI registry entry for 78:CA:5E. This is the address the organization registered with the IEEE, which may differ from its current operating address.

ELNO

MAC address prefix 78:CA:5E is registered to ELNO in the IEEE OUI registry. Any device whose MAC address begins with 78:CA:5E has a network interface built by ELNO. 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 78:CA:5E:00:00:00 to 78:CA:5E:FF:FF:FF.

OUI prefix: 78:CA:5E
Hyphen form: 78-CA-5E
MAC range: 78:CA:5E:00:00:00 – 78:CA:5E:FF:FF:FF
Addresses in block: 16,777,216
Organization: ELNO
Address: 43 rue Michel Carré Argenteuil - US F95102
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 "ELNO"
archived source →
2026-07-17Assigned to "ELNO"

Nearby in the registry

The prefixes assigned immediately before and after 78:CA:5E:

FAQ

Which company owns MAC address prefix 78:CA:5E?: MAC address prefix 78:CA:5E is registered to ELNO in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 78:CA:5E has a network interface built by ELNO.
What is the OUI 78:CA:5E?: 78:CA:5E is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to ELNO. It covers every address from 78:CA:5E:00:00:00 to 78:CA:5E:FF:FF:FF, or 16,777,216 addresses in total. It is also written 78-CA-5E.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 78:CA:5E:00:00:00 that is 78:CA:5E — 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 ELNO located?: ELNO is listed at 43 rue Michel Carré Argenteuil - US F95102 in the IEEE OUI registry entry for 78:CA:5E. This is the address the organization registered with the IEEE, which may differ from its current operating address.