What this means
The IEEE assigned the MA-L block 001991 to avinfo. 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 00:19:91, it is avinfo hardware.
Frequently Asked Questions
Who owns MAC prefix 001991?
001991 is registered to avinfo 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. avinfo's block covers 16,777,216 addresses.
What devices use 001991?
Any network device with a MAC address starting 00:19:91 was manufactured by or for avinfo.