What this means
The IEEE assigned the MA-S block 8C1F6433D to ARROW (CHINA) ELECTRONICS TRADING 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 8C:1F:64:33:D, it is ARROW (CHINA) ELECTRONICS TRADING CO., LTD. hardware.