Which company owns MAC address prefix 04:3A:0D?

MAC address prefix 04:3A:0D is registered to SM Optics S.r.l. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 04:3A:0D has a network interface built by SM Optics S.r.l..

What is the OUI 04:3A:0D?

04:3A:0D is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to SM Optics S.r.l.. It covers every address from 04:3A:0D:00:00:00 to 04:3A:0D:FF:FF:FF, or 16,777,216 addresses in total. It is also written 04-3A-0D.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 04:3A:0D:00:00:00 that is 04:3A:0D — 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 SM Optics S.r.l. located?

SM Optics S.r.l. is listed at via Michelangelo Buonarroti, 1 Cologno Monzese Milan IT I-20093 in the IEEE OUI registry entry for 04:3A:0D. This is the address the organization registered with the IEEE, which may differ from its current operating address.

SM Optics S.r.l.

MAC address prefix 04:3A:0D is registered to SM Optics S.r.l. in the IEEE OUI registry. Any device whose MAC address begins with 04:3A:0D has a network interface built by SM Optics S.r.l.. 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 04:3A:0D:00:00:00 to 04:3A:0D:FF:FF:FF.

OUI prefix: 04:3A:0D
Hyphen form: 04-3A-0D
MAC range: 04:3A:0D:00:00:00 – 04:3A:0D:FF:FF:FF
Addresses in block: 16,777,216
Organization: SM Optics S.r.l.
Address: via Michelangelo Buonarroti, 1 Cologno Monzese Milan IT I-20093
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.

2017-09-08Assigned to "SM Optics S.r.l."
archived source →
2026-07-17Assigned to "SM Optics S.r.l."

Nearby in the registry

The prefixes assigned immediately before and after 04:3A:0D:

FAQ

Which company owns MAC address prefix 04:3A:0D?: MAC address prefix 04:3A:0D is registered to SM Optics S.r.l. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 04:3A:0D has a network interface built by SM Optics S.r.l..
What is the OUI 04:3A:0D?: 04:3A:0D is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to SM Optics S.r.l.. It covers every address from 04:3A:0D:00:00:00 to 04:3A:0D:FF:FF:FF, or 16,777,216 addresses in total. It is also written 04-3A-0D.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 04:3A:0D:00:00:00 that is 04:3A:0D — 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 SM Optics S.r.l. located?: SM Optics S.r.l. is listed at via Michelangelo Buonarroti, 1 Cologno Monzese Milan IT I-20093 in the IEEE OUI registry entry for 04:3A:0D. This is the address the organization registered with the IEEE, which may differ from its current operating address.