What this means
The IEEE assigned the MA-L block B4CEFE to James Czekaj. 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:CE:FE, it is James Czekaj hardware.
Frequently Asked Questions
Who owns MAC prefix B4CEFE?
B4CEFE is registered to James Czekaj 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. James Czekaj's block covers 16,777,216 addresses.
What devices use B4CEFE?
Any network device with a MAC address starting B4:CE:FE was manufactured by or for James Czekaj.