What this means
The IEEE assigned the MA-M block 643139B to Alphago GmbH. 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 64:31:39:B, it is Alphago GmbH hardware.
Frequently Asked Questions
Who owns MAC prefix 643139B?
643139B is registered to Alphago GmbH 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. Alphago GmbH's block covers 1,048,576 addresses.
What devices use 643139B?
Any network device with a MAC address starting 64:31:39:B was manufactured by or for Alphago GmbH.