Which company owns MAC address prefix 08:EF:3B?

MAC address prefix 08:EF:3B is registered to MCS Logic Inc. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 08:EF:3B has a network interface built by MCS Logic Inc..

What is the OUI 08:EF:3B?

08:EF:3B is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to MCS Logic Inc.. It covers every address from 08:EF:3B:00:00:00 to 08:EF:3B:FF:FF:FF, or 16,777,216 addresses in total. It is also written 08-EF-3B.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 08:EF:3B:00:00:00 that is 08:EF:3B — 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 MCS Logic Inc. located?

MCS Logic Inc. is listed at 6F. Samho Center B Bldg., 275-6,Yangjae-Dong, Secho-Ku,Seoul Seoul KR 137-941 in the IEEE OUI registry entry for 08:EF:3B. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does MCS Logic Inc. own?

MCS Logic Inc. holds 4 OUI prefixes in the IEEE registry, of which 08:EF:3B is one. A device made by MCS Logic Inc. could carry a MAC address from any of them.

MCS Logic Inc.

MAC address prefix 08:EF:3B is registered to MCS Logic Inc. in the IEEE OUI registry. Any device whose MAC address begins with 08:EF:3B has a network interface built by MCS Logic Inc.. 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 08:EF:3B:00:00:00 to 08:EF:3B:FF:FF:FF.

OUI prefix: 08:EF:3B
Hyphen form: 08-EF-3B
MAC range: 08:EF:3B:00:00:00 – 08:EF:3B:FF:FF:FF
Addresses in block: 16,777,216
Organization: MCS Logic Inc.
Address: 6F. Samho Center B Bldg., 275-6,Yangjae-Dong, Secho-Ku,Seoul Seoul KR 137-941
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 MCS Logic Inc.

MCS Logic Inc. holds 4 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 "MCS Logic Inc."
archived source →
2026-07-17Assigned to "MCS Logic Inc."

Nearby in the registry

The prefixes assigned immediately before and after 08:EF:3B:

FAQ

Which company owns MAC address prefix 08:EF:3B?: MAC address prefix 08:EF:3B is registered to MCS Logic Inc. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 08:EF:3B has a network interface built by MCS Logic Inc..
What is the OUI 08:EF:3B?: 08:EF:3B is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to MCS Logic Inc.. It covers every address from 08:EF:3B:00:00:00 to 08:EF:3B:FF:FF:FF, or 16,777,216 addresses in total. It is also written 08-EF-3B.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 08:EF:3B:00:00:00 that is 08:EF:3B — 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 MCS Logic Inc. located?: MCS Logic Inc. is listed at 6F. Samho Center B Bldg., 275-6,Yangjae-Dong, Secho-Ku,Seoul Seoul KR 137-941 in the IEEE OUI registry entry for 08:EF:3B. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does MCS Logic Inc. own?: MCS Logic Inc. holds 4 OUI prefixes in the IEEE registry, of which 08:EF:3B is one. A device made by MCS Logic Inc. could carry a MAC address from any of them.