Which company owns MAC address prefix 78:CB:2C?

MAC address prefix 78:CB:2C is registered to Join Digital, Inc. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 78:CB:2C has a network interface built by Join Digital, Inc..

What is the OUI 78:CB:2C?

78:CB:2C is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Join Digital, Inc.. It covers every address from 78:CB:2C:00:00:00 to 78:CB:2C:FF:FF:FF, or 16,777,216 addresses in total. It is also written 78-CB-2C.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 78:CB:2C:00:00:00 that is 78:CB:2C — 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 Join Digital, Inc. located?

Join Digital, Inc. is listed at 75 E Santa Clara St., 6th Floor San Jose CA US 95113 in the IEEE OUI registry entry for 78:CB:2C. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Join Digital, Inc.

MAC address prefix 78:CB:2C is registered to Join Digital, Inc. in the IEEE OUI registry. Any device whose MAC address begins with 78:CB:2C has a network interface built by Join Digital, 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 78:CB:2C:00:00:00 to 78:CB:2C:FF:FF:FF.

OUI prefix: 78:CB:2C
Hyphen form: 78-CB-2C
MAC range: 78:CB:2C:00:00:00 – 78:CB:2C:FF:FF:FF
Addresses in block: 16,777,216
Organization: Join Digital, Inc.
Address: 75 E Santa Clara St., 6th Floor San Jose CA US 95113
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.

2020-11-28Assigned to "Join Digital, Inc."
archived source →
2026-07-17Assigned to "Join Digital, Inc."

Nearby in the registry

The prefixes assigned immediately before and after 78:CB:2C:

FAQ

Which company owns MAC address prefix 78:CB:2C?: MAC address prefix 78:CB:2C is registered to Join Digital, Inc. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 78:CB:2C has a network interface built by Join Digital, Inc..
What is the OUI 78:CB:2C?: 78:CB:2C is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Join Digital, Inc.. It covers every address from 78:CB:2C:00:00:00 to 78:CB:2C:FF:FF:FF, or 16,777,216 addresses in total. It is also written 78-CB-2C.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 78:CB:2C:00:00:00 that is 78:CB:2C — 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 Join Digital, Inc. located?: Join Digital, Inc. is listed at 75 E Santa Clara St., 6th Floor San Jose CA US 95113 in the IEEE OUI registry entry for 78:CB:2C. This is the address the organization registered with the IEEE, which may differ from its current operating address.