What this means
The IEEE assigned the MA-L block E42F56 to OptoMET GmbH. 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 E4:2F:56, it is OptoMET GmbH hardware.
Frequently Asked Questions
Who owns MAC prefix E42F56?
E42F56 is registered to OptoMET GmbH 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. OptoMET GmbH's block covers 16,777,216 addresses.
What devices use E42F56?
Any network device with a MAC address starting E4:2F:56 was manufactured by or for OptoMET GmbH.