What this means
The IEEE assigned the MA-L block 7491BD to Four systems Co.,Ltd.. 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 74:91:BD, it is Four systems Co.,Ltd. hardware.
Frequently Asked Questions
Who owns MAC prefix 7491BD?
7491BD is registered to Four systems Co.,Ltd. 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. Four systems Co.,Ltd.'s block covers 16,777,216 addresses.
What devices use 7491BD?
Any network device with a MAC address starting 74:91:BD was manufactured by or for Four systems Co.,Ltd..