Which company owns MAC address prefix 20:E7:91?

MAC address prefix 20:E7:91 is registered to Siemens Healthcare Diagnostics, Inc in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 20:E7:91 has a network interface built by Siemens Healthcare Diagnostics, Inc.

What is the OUI 20:E7:91?

20:E7:91 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Siemens Healthcare Diagnostics, Inc. It covers every address from 20:E7:91:00:00:00 to 20:E7:91:FF:FF:FF, or 16,777,216 addresses in total. It is also written 20-E7-91.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 20:E7:91:00:00:00 that is 20:E7:91 — 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 Siemens Healthcare Diagnostics, Inc located?

Siemens Healthcare Diagnostics, Inc is listed at 2 Edgewater Drive Norwood MA US 02062 in the IEEE OUI registry entry for 20:E7:91. This is the address the organization registered with the IEEE, which may differ from its current operating address.

Siemens Healthcare Diagnostics, Inc

MAC address prefix 20:E7:91 is registered to Siemens Healthcare Diagnostics, Inc in the IEEE OUI registry. Any device whose MAC address begins with 20:E7:91 has a network interface built by Siemens Healthcare Diagnostics, 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 20:E7:91:00:00:00 to 20:E7:91:FF:FF:FF.

OUI prefix: 20:E7:91
Hyphen form: 20-E7-91
MAC range: 20:E7:91:00:00:00 – 20:E7:91:FF:FF:FF
Addresses in block: 16,777,216
Organization: Siemens Healthcare Diagnostics, Inc
Address: 2 Edgewater Drive Norwood MA US 02062
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 "Siemens Healthcare Diagnostics, Inc"
archived source →
2026-07-17Assigned to "Siemens Healthcare Diagnostics, Inc"

Nearby in the registry

The prefixes assigned immediately before and after 20:E7:91:

FAQ

Which company owns MAC address prefix 20:E7:91?: MAC address prefix 20:E7:91 is registered to Siemens Healthcare Diagnostics, Inc in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 20:E7:91 has a network interface built by Siemens Healthcare Diagnostics, Inc.
What is the OUI 20:E7:91?: 20:E7:91 is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to Siemens Healthcare Diagnostics, Inc. It covers every address from 20:E7:91:00:00:00 to 20:E7:91:FF:FF:FF, or 16,777,216 addresses in total. It is also written 20-E7-91.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 20:E7:91:00:00:00 that is 20:E7:91 — 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 Siemens Healthcare Diagnostics, Inc located?: Siemens Healthcare Diagnostics, Inc is listed at 2 Edgewater Drive Norwood MA US 02062 in the IEEE OUI registry entry for 20:E7:91. This is the address the organization registered with the IEEE, which may differ from its current operating address.