What this means
The IEEE assigned the MA-L block 00025B to Cambridge Silicon Radio. 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 00:02:5B, it is Cambridge Silicon Radio hardware.
Frequently Asked Questions
Who owns MAC prefix 00025B?
00025B is registered to Cambridge Silicon Radio 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. Cambridge Silicon Radio's block covers 16,777,216 addresses.
What devices use 00025B?
Any network device with a MAC address starting 00:02:5B was manufactured by or for Cambridge Silicon Radio.