Which company owns MAC address prefix 18:D5:B6?

MAC address prefix 18:D5:B6 is registered to SMG Holdings LLC in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 18:D5:B6 has a network interface built by SMG Holdings LLC.

What is the OUI 18:D5:B6?

18:D5:B6 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to SMG Holdings LLC. It covers every address from 18:D5:B6:00:00:00 to 18:D5:B6:FF:FF:FF, or 16,777,216 addresses in total. It is also written 18-D5-B6.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 18:D5:B6:00:00:00 that is 18:D5:B6 — 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 SMG Holdings LLC located?

SMG Holdings LLC is listed at 205 N Michigan Ave Chicago IL US 60601 in the IEEE OUI registry entry for 18:D5:B6. This is the address the organization registered with the IEEE, which may differ from its current operating address.

SMG Holdings LLC

MAC address prefix 18:D5:B6 is registered to SMG Holdings LLC in the IEEE OUI registry. Any device whose MAC address begins with 18:D5:B6 has a network interface built by SMG Holdings LLC. 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 18:D5:B6:00:00:00 to 18:D5:B6:FF:FF:FF.

OUI prefix: 18:D5:B6
Hyphen form: 18-D5-B6
MAC range: 18:D5:B6:00:00:00 – 18:D5:B6:FF:FF:FF
Addresses in block: 16,777,216
Organization: SMG Holdings LLC
Address: 205 N Michigan Ave Chicago IL US 60601
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 "SMG Holdings LLC"
archived source →
2026-07-17Assigned to "SMG Holdings LLC"

Nearby in the registry

The prefixes assigned immediately before and after 18:D5:B6:

FAQ

Which company owns MAC address prefix 18:D5:B6?: MAC address prefix 18:D5:B6 is registered to SMG Holdings LLC in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 18:D5:B6 has a network interface built by SMG Holdings LLC.
What is the OUI 18:D5:B6?: 18:D5:B6 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to SMG Holdings LLC. It covers every address from 18:D5:B6:00:00:00 to 18:D5:B6:FF:FF:FF, or 16,777,216 addresses in total. It is also written 18-D5-B6.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 18:D5:B6:00:00:00 that is 18:D5:B6 — 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 SMG Holdings LLC located?: SMG Holdings LLC is listed at 205 N Michigan Ave Chicago IL US 60601 in the IEEE OUI registry entry for 18:D5:B6. This is the address the organization registered with the IEEE, which may differ from its current operating address.