What this means
The IEEE assigned the MA-L block B4E1C4 to Microsoft Mobile Oy. 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 B4:E1:C4, it is Microsoft Mobile Oy hardware.
Frequently Asked Questions
Who owns MAC prefix B4E1C4?
B4E1C4 is registered to Microsoft Mobile Oy 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 Mobile Oy's block covers 16,777,216 addresses.
What devices use B4E1C4?
Any network device with a MAC address starting B4:E1:C4 was manufactured by or for Microsoft Mobile Oy.