What this means
The IEEE assigned the MA-L block 4012E4 to Compass-EOS. 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 40:12:E4, it is Compass-EOS hardware.
Frequently Asked Questions
Who owns MAC prefix 4012E4?
4012E4 is registered to Compass-EOS 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. Compass-EOS's block covers 16,777,216 addresses.
What devices use 4012E4?
Any network device with a MAC address starting 40:12:E4 was manufactured by or for Compass-EOS.