What this means
The IEEE assigned the MA-L block C4C19F to National Oilwell Varco Instrumentation, Monitoring, and Optimization (NOV IMO). 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 C4:C1:9F, it is National Oilwell Varco Instrumentation, Monitoring, and Optimization (NOV IMO) hardware.
Frequently Asked Questions
Who owns MAC prefix C4C19F?
C4C19F is registered to National Oilwell Varco Instrumentation, Monitoring, and Optimization (NOV IMO) 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. National Oilwell Varco Instrumentation, Monitoring, and Optimization (NOV IMO)'s block covers 16,777,216 addresses.
What devices use C4C19F?
Any network device with a MAC address starting C4:C1:9F was manufactured by or for National Oilwell Varco Instrumentation, Monitoring, and Optimization (NOV IMO).