What this means
The IEEE assigned the MA-L block 40F2E9 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 40:F2:E9, it is IBM hardware.
Frequently Asked Questions
Who owns MAC prefix 40F2E9?
40F2E9 is registered to IBM 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. IBM's block covers 16,777,216 addresses.
What devices use 40F2E9?
Any network device with a MAC address starting 40:F2:E9 was manufactured by or for IBM.