What this means
The IEEE assigned the MA-M block B437D12 to Fibersystem AB. 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 B4:37:D1:2, it is Fibersystem AB hardware.
Frequently Asked Questions
Who owns MAC prefix B437D12?
B437D12 is registered to Fibersystem AB in the IEEE MA-M registry.
What does the MA-M registry type mean?
An MA-M assignment covers 28 bits of the address, giving the vendor 1,048,576 device addresses, a quarter of a full MA-L block. Fibersystem AB's block covers 1,048,576 addresses.
What devices use B437D12?
Any network device with a MAC address starting B4:37:D1:2 was manufactured by or for Fibersystem AB.