Which company owns MAC address prefix 4C:D4:B1?

MAC address prefix 4C:D4:B1 is registered to NXP Semiconductor (Tianjin) LTD. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 4C:D4:B1 has a network interface built by NXP Semiconductor (Tianjin) LTD..

What is the OUI 4C:D4:B1?

4C:D4:B1 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to NXP Semiconductor (Tianjin) LTD.. It covers every address from 4C:D4:B1:00:00:00 to 4C:D4:B1:FF:FF:FF, or 16,777,216 addresses in total. It is also written 4C-D4-B1.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 4C:D4:B1:00:00:00 that is 4C:D4:B1 — 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 NXP Semiconductor (Tianjin) LTD. located?

NXP Semiconductor (Tianjin) LTD. is listed at No.15 Xinghua Avenue, Xiqing Economic Development Area Tianjin CN 300385 in the IEEE OUI registry entry for 4C:D4:B1. This is the address the organization registered with the IEEE, which may differ from its current operating address.

How many MAC prefixes does NXP Semiconductor (Tianjin) LTD. own?

NXP Semiconductor (Tianjin) LTD. holds 23 OUI prefixes in the IEEE registry, of which 4C:D4:B1 is one. A device made by NXP Semiconductor (Tianjin) LTD. could carry a MAC address from any of them.

NXP Semiconductor (Tianjin) LTD.

MAC address prefix 4C:D4:B1 is registered to NXP Semiconductor (Tianjin) LTD. in the IEEE OUI registry. Any device whose MAC address begins with 4C:D4:B1 has a network interface built by NXP Semiconductor (Tianjin) 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 4C:D4:B1:00:00:00 to 4C:D4:B1:FF:FF:FF.

OUI prefix: 4C:D4:B1
Hyphen form: 4C-D4-B1
MAC range: 4C:D4:B1:00:00:00 – 4C:D4:B1:FF:FF:FF
Addresses in block: 16,777,216
Organization: NXP Semiconductor (Tianjin) LTD.
Address: No.15 Xinghua Avenue, Xiqing Economic Development Area Tianjin CN 300385
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.

Other prefixes from NXP Semiconductor (Tianjin) LTD.

NXP Semiconductor (Tianjin) LTD. holds 23 OUI prefixes in total. A device with this exact prefix could just as well carry any of these:

Assignment history (2)

The IEEE registry publishes current state only — this is the change record we've kept since we started tracking it daily.

2026-01-08Assigned to "NXP Semiconductor (Tianjin) LTD."
archived source →
2026-07-17Assigned to "NXP Semiconductor (Tianjin) LTD."

Nearby in the registry

The prefixes assigned immediately before and after 4C:D4:B1:

FAQ

Which company owns MAC address prefix 4C:D4:B1?: MAC address prefix 4C:D4:B1 is registered to NXP Semiconductor (Tianjin) LTD. in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 4C:D4:B1 has a network interface built by NXP Semiconductor (Tianjin) LTD..
What is the OUI 4C:D4:B1?: 4C:D4:B1 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to NXP Semiconductor (Tianjin) LTD.. It covers every address from 4C:D4:B1:00:00:00 to 4C:D4:B1:FF:FF:FF, or 16,777,216 addresses in total. It is also written 4C-D4-B1.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 4C:D4:B1:00:00:00 that is 4C:D4:B1 — 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 NXP Semiconductor (Tianjin) LTD. located?: NXP Semiconductor (Tianjin) LTD. is listed at No.15 Xinghua Avenue, Xiqing Economic Development Area Tianjin CN 300385 in the IEEE OUI registry entry for 4C:D4:B1. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does NXP Semiconductor (Tianjin) LTD. own?: NXP Semiconductor (Tianjin) LTD. holds 23 OUI prefixes in the IEEE registry, of which 4C:D4:B1 is one. A device made by NXP Semiconductor (Tianjin) LTD. could carry a MAC address from any of them.