Which company owns MAC address prefix 5C:5D:EC?

MAC address prefix 5C:5D:EC is registered to JiangSu Newcom Optical&Electrical Communication CO Ltd in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 5C:5D:EC has a network interface built by JiangSu Newcom Optical&Electrical Communication CO Ltd.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 5C:5D:EC:00:00:00 that is 5C:5D:EC — 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.

JiangSu Newcom Optical&Electrical Communication CO Ltd

MAC address prefix 5C:5D:EC is registered to JiangSu Newcom Optical&Electrical Communication CO Ltd in the IEEE OUI registry. Any device whose MAC address begins with 5C:5D:EC has a network interface built by JiangSu Newcom Optical&Electrical Communication 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 5C:5D:EC:00:00:00 to 5C:5D:EC:FF:FF:FF.

OUI prefix: 5C:5D:EC
Hyphen form: 5C-5D-EC
MAC range: 5C:5D:EC:00:00:00 – 5C:5D:EC:FF:FF:FF
Addresses in block: 16,777,216
Organization: JiangSu Newcom Optical&Electrical Communication CO Ltd
Address: 17F, Guyang Century Mansion, NO 600 Zhujiang Road Nanjing JiangSu CN 210018
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.

2024-07-02Assigned to "JiangSu Newcom Optical&Electrical Communication CO Ltd"
archived source →
2026-07-17Assigned to "JiangSu Newcom Optical&Electrical Communication CO Ltd"

Nearby in the registry

The prefixes assigned immediately before and after 5C:5D:EC:

FAQ

Which company owns MAC address prefix 5C:5D:EC?: MAC address prefix 5C:5D:EC is registered to JiangSu Newcom Optical&Electrical Communication CO Ltd in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 5C:5D:EC has a network interface built by JiangSu Newcom Optical&Electrical Communication CO Ltd.
What is the OUI 5C:5D:EC?: 5C:5D:EC is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to JiangSu Newcom Optical&Electrical Communication CO Ltd. It covers every address from 5C:5D:EC:00:00:00 to 5C:5D:EC:FF:FF:FF, or 16,777,216 addresses in total. It is also written 5C-5D-EC.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 5C:5D:EC:00:00:00 that is 5C:5D:EC — 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 Newcom Optical&Electrical Communication CO Ltd located?: JiangSu Newcom Optical&Electrical Communication CO Ltd is listed at 17F, Guyang Century Mansion, NO 600 Zhujiang Road Nanjing JiangSu CN 210018 in the IEEE OUI registry entry for 5C:5D:EC. This is the address the organization registered with the IEEE, which may differ from its current operating address.