What this means
The IEEE assigned the MA-S block 8C1F648A9 to Guan Show Technologe 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:64:8A:9, it is Guan Show Technologe Co., Ltd. hardware.