Which company owns MAC address prefix 78:30:3B?

MAC address prefix 78:30:3B is registered to Stephen Technologies Co.,Limited in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 78:30:3B has a network interface built by Stephen Technologies Co.,Limited.

What is the OUI 78:30:3B?

78:30:3B is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Stephen Technologies Co.,Limited. It covers every address from 78:30:3B:00:00:00 to 78:30:3B:FF:FF:FF, or 16,777,216 addresses in total. It is also written 78-30-3B.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 78:30:3B:00:00:00 that is 78:30:3B — 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 Stephen Technologies Co.,Limited located?

Stephen Technologies Co.,Limited is listed at 5/F, Building NO.1, TongXin Industry Zone Shenzhen Guangdong CN 518115 in the IEEE OUI registry entry for 78:30:3B. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Stephen Technologies Co.,Limited

MAC address prefix 78:30:3B is registered to Stephen Technologies Co.,Limited in the IEEE OUI registry. Any device whose MAC address begins with 78:30:3B has a network interface built by Stephen Technologies Co.,Limited. 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 78:30:3B:00:00:00 to 78:30:3B:FF:FF:FF.

OUI prefix: 78:30:3B
Hyphen form: 78-30-3B
MAC range: 78:30:3B:00:00:00 – 78:30:3B:FF:FF:FF
Addresses in block: 16,777,216
Organization: Stephen Technologies Co.,Limited
Address: 5/F, Building NO.1, TongXin Industry Zone Shenzhen Guangdong CN 518115
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 "Stephen Technologies Co.,Limited"
archived source →
2026-07-17Assigned to "Stephen Technologies Co.,Limited"

Nearby in the registry

The prefixes assigned immediately before and after 78:30:3B:

FAQ

Which company owns MAC address prefix 78:30:3B?: MAC address prefix 78:30:3B is registered to Stephen Technologies Co.,Limited in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 78:30:3B has a network interface built by Stephen Technologies Co.,Limited.
What is the OUI 78:30:3B?: 78:30:3B is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Stephen Technologies Co.,Limited. It covers every address from 78:30:3B:00:00:00 to 78:30:3B:FF:FF:FF, or 16,777,216 addresses in total. It is also written 78-30-3B.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 78:30:3B:00:00:00 that is 78:30:3B — 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 Stephen Technologies Co.,Limited located?: Stephen Technologies Co.,Limited is listed at 5/F, Building NO.1, TongXin Industry Zone Shenzhen Guangdong CN 518115 in the IEEE OUI registry entry for 78:30:3B. This is the address the organization registered with the IEEE, which may differ from its current operating address.