Which company owns MAC address prefix 38:87:9C?

MAC address prefix 38:87:9C is registered to Ei Electronics in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 38:87:9C has a network interface built by Ei Electronics.

What is the OUI 38:87:9C?

38:87:9C is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Ei Electronics. It covers every address from 38:87:9C:00:00:00 to 38:87:9C:FF:FF:FF, or 16,777,216 addresses in total. It is also written 38-87-9C.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 38:87:9C:00:00:00 that is 38:87:9C — 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 Ei Electronics located?

Ei Electronics is listed at Unit 40-47 Shannon Industrial Estate Shannon Co. Clare IE V14 H020 in the IEEE OUI registry entry for 38:87:9C. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Ei Electronics

MAC address prefix 38:87:9C is registered to Ei Electronics in the IEEE OUI registry. Any device whose MAC address begins with 38:87:9C has a network interface built by Ei Electronics. 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 38:87:9C:00:00:00 to 38:87:9C:FF:FF:FF.

OUI prefix: 38:87:9C
Hyphen form: 38-87-9C
MAC range: 38:87:9C:00:00:00 – 38:87:9C:FF:FF:FF
Addresses in block: 16,777,216
Organization: Ei Electronics
Address: Unit 40-47 Shannon Industrial Estate Shannon Co. Clare IE V14 H020
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.

2026-06-20Assigned to "Ei Electronics"
archived source →
2026-07-17Assigned to "Ei Electronics"

Nearby in the registry

The prefixes assigned immediately before and after 38:87:9C:

FAQ

Which company owns MAC address prefix 38:87:9C?: MAC address prefix 38:87:9C is registered to Ei Electronics in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 38:87:9C has a network interface built by Ei Electronics.
What is the OUI 38:87:9C?: 38:87:9C is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Ei Electronics. It covers every address from 38:87:9C:00:00:00 to 38:87:9C:FF:FF:FF, or 16,777,216 addresses in total. It is also written 38-87-9C.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 38:87:9C:00:00:00 that is 38:87:9C — 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 Ei Electronics located?: Ei Electronics is listed at Unit 40-47 Shannon Industrial Estate Shannon Co. Clare IE V14 H020 in the IEEE OUI registry entry for 38:87:9C. This is the address the organization registered with the IEEE, which may differ from its current operating address.