What this means
The IEEE assigned the MA-L block B4EF30 to Shanghai SYH Technology 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 B4:EF:30, it is Shanghai SYH Technology CO.,LTD hardware.
Frequently Asked Questions
Who owns MAC prefix B4EF30?
B4EF30 is registered to Shanghai SYH Technology 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. Shanghai SYH Technology CO.,LTD's block covers 16,777,216 addresses.
What devices use B4EF30?
Any network device with a MAC address starting B4:EF:30 was manufactured by or for Shanghai SYH Technology CO.,LTD.