Which company owns MAC address prefix 44:38:39?

MAC address prefix 44:38:39 is registered to Cumulus Networks, inc in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 44:38:39 has a network interface built by Cumulus Networks, inc.

What is the OUI 44:38:39?

44:38:39 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Cumulus Networks, inc. It covers every address from 44:38:39:00:00:00 to 44:38:39:FF:FF:FF, or 16,777,216 addresses in total. It is also written 44-38-39.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 44:38:39:00:00:00 that is 44:38:39 — 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 Cumulus Networks, inc located?

Cumulus Networks, inc is listed at 650 Castro Street, suite 120-245 Mountain View CA US 94041 in the IEEE OUI registry entry for 44:38:39. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Cumulus Networks, inc

MAC address prefix 44:38:39 is registered to Cumulus Networks, inc in the IEEE OUI registry. Any device whose MAC address begins with 44:38:39 has a network interface built by Cumulus Networks, inc. 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 44:38:39:00:00:00 to 44:38:39:FF:FF:FF.

OUI prefix: 44:38:39
Hyphen form: 44-38-39
MAC range: 44:38:39:00:00:00 – 44:38:39:FF:FF:FF
Addresses in block: 16,777,216
Organization: Cumulus Networks, inc
Address: 650 Castro Street, suite 120-245 Mountain View CA US 94041
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 "Cumulus Networks, inc"
archived source →
2026-07-17Assigned to "Cumulus Networks, inc"

Nearby in the registry

The prefixes assigned immediately before and after 44:38:39:

FAQ

Which company owns MAC address prefix 44:38:39?: MAC address prefix 44:38:39 is registered to Cumulus Networks, inc in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 44:38:39 has a network interface built by Cumulus Networks, inc.
What is the OUI 44:38:39?: 44:38:39 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Cumulus Networks, inc. It covers every address from 44:38:39:00:00:00 to 44:38:39:FF:FF:FF, or 16,777,216 addresses in total. It is also written 44-38-39.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 44:38:39:00:00:00 that is 44:38:39 — 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 Cumulus Networks, inc located?: Cumulus Networks, inc is listed at 650 Castro Street, suite 120-245 Mountain View CA US 94041 in the IEEE OUI registry entry for 44:38:39. This is the address the organization registered with the IEEE, which may differ from its current operating address.