Which company owns MAC address prefix 30:A3:B5?

MAC address prefix 30:A3:B5 is registered to Jiangsu Best Tone Information Service Co., Ltd in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 30:A3:B5 has a network interface built by Jiangsu Best Tone Information Service Co., Ltd.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 30:A3:B5:00:00:00 that is 30:A3:B5 — 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 Jiangsu Best Tone Information Service Co., Ltd located?

Jiangsu Best Tone Information Service Co., Ltd is listed at No.501,Zhongshan South Road Nanjing Jiangsu CN 210006 in the IEEE OUI registry entry for 30:A3:B5. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Jiangsu Best Tone Information Service Co., Ltd

MAC address prefix 30:A3:B5 is registered to Jiangsu Best Tone Information Service Co., Ltd in the IEEE OUI registry. Any device whose MAC address begins with 30:A3:B5 has a network interface built by Jiangsu Best Tone Information Service Co., Ltd. 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 30:A3:B5:00:00:00 to 30:A3:B5:FF:FF:FF.

OUI prefix: 30:A3:B5
Hyphen form: 30-A3-B5
MAC range: 30:A3:B5:00:00:00 – 30:A3:B5:FF:FF:FF
Addresses in block: 16,777,216
Organization: Jiangsu Best Tone Information Service Co., Ltd
Address: No.501,Zhongshan South Road Nanjing Jiangsu CN 210006
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.

2024-02-15Assigned to "Jiangsu Best Tone Information Service Co., Ltd"
archived source →
2026-07-17Assigned to "Jiangsu Best Tone Information Service Co., Ltd"

Nearby in the registry

The prefixes assigned immediately before and after 30:A3:B5:

FAQ

Which company owns MAC address prefix 30:A3:B5?: MAC address prefix 30:A3:B5 is registered to Jiangsu Best Tone Information Service Co., Ltd in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 30:A3:B5 has a network interface built by Jiangsu Best Tone Information Service Co., Ltd.
What is the OUI 30:A3:B5?: 30:A3:B5 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Jiangsu Best Tone Information Service Co., Ltd. It covers every address from 30:A3:B5:00:00:00 to 30:A3:B5:FF:FF:FF, or 16,777,216 addresses in total. It is also written 30-A3-B5.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 30:A3:B5:00:00:00 that is 30:A3:B5 — 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 Jiangsu Best Tone Information Service Co., Ltd located?: Jiangsu Best Tone Information Service Co., Ltd is listed at No.501,Zhongshan South Road Nanjing Jiangsu CN 210006 in the IEEE OUI registry entry for 30:A3:B5. This is the address the organization registered with the IEEE, which may differ from its current operating address.