What this means
The IEEE assigned the MA-L block 002091 to J125, NATIONAL SECURITY AGENCY. 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 00:20:91, it is J125, NATIONAL SECURITY AGENCY hardware.
Frequently Asked Questions
Who owns MAC prefix 002091?
002091 is registered to J125, NATIONAL SECURITY AGENCY 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. J125, NATIONAL SECURITY AGENCY's block covers 16,777,216 addresses.
What devices use 002091?
Any network device with a MAC address starting 00:20:91 was manufactured by or for J125, NATIONAL SECURITY AGENCY.