Who owns MAC prefix B4EF30?

B4EF30 is registered to Shanghai SYH Technology CO.,LTD in the IEEE MA-L registry.

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.

MA-L · OUI prefix

Shanghai SYH Technology CO.,LTD

Any MAC address starting B4:EF:30 is registered to Shanghai SYH Technology CO.,LTD in CN.

OUI prefix	B4EF30
Vendor	Shanghai SYH Technology CO.,LTD
Registry	MA-L (24-bit, large block)
Country	CN
Example MAC	B4:EF:30:00:00:00

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.

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