What this means
The IEEE assigned the MA-L block 2091DF to Apple, Inc.. 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 20:91:DF, it is Apple, Inc. hardware.
Frequently Asked Questions
Who owns MAC prefix 2091DF?
2091DF is registered to Apple, Inc. 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. Apple, Inc.'s block covers 16,777,216 addresses.
What devices use 2091DF?
Any network device with a MAC address starting 20:91:DF was manufactured by or for Apple, Inc..