What this means
The IEEE assigned the MA-L block 000F40 to Optical Internetworking Forum. 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 00:0F:40, it is Optical Internetworking Forum hardware.
Frequently Asked Questions
Who owns MAC prefix 000F40?
000F40 is registered to Optical Internetworking Forum 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. Optical Internetworking Forum's block covers 16,777,216 addresses.
What devices use 000F40?
Any network device with a MAC address starting 00:0F:40 was manufactured by or for Optical Internetworking Forum.