What this means
The IEEE assigned the MA-L block B831B5 to Microsoft Corporation. Every network interface they manufacture under this block has a MAC address beginning with these digits, followed by a unique per-device identifier. If a device on your network shows a MAC starting B8:31:B5, it is Microsoft Corporation hardware.
Frequently Asked Questions
Who owns MAC prefix B831B5?
B831B5 is registered to Microsoft Corporation in the IEEE MA-L registry.
What does the MA-L registry type mean?
An MA-L assignment, the IEEE's original OUI format, gives the vendor the first three octets and 16,777,216 device addresses under them. Microsoft Corporation's block covers 16,777,216 addresses.
What devices use B831B5?
Any network device with a MAC address starting B8:31:B5 was manufactured by or for Microsoft Corporation.