What this means
The IEEE assigned the MA-M block C4FF848 to IBM. 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 C4:FF:84:8, it is IBM hardware.
Frequently Asked Questions
Who owns MAC prefix C4FF848?
C4FF848 is registered to IBM 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. IBM's block covers 1,048,576 addresses.
What devices use C4FF848?
Any network device with a MAC address starting C4:FF:84:8 was manufactured by or for IBM.