What this means
The IEEE assigned the MA-M block 3C6A2C4 to XI'AN YEP TELECOM 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 3C:6A:2C:4, it is XI'AN YEP TELECOM TECHNOLOGY CO.,LTD hardware.