What this means
The IEEE assigned the MA-L block F40F1B to Cisco Systems, Inc. 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 F4:0F:1B, it is Cisco Systems, Inc hardware.
Frequently Asked Questions
Who owns MAC prefix F40F1B?
F40F1B is registered to Cisco Systems, Inc 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. Cisco Systems, Inc's block covers 16,777,216 addresses.
What devices use F40F1B?
Any network device with a MAC address starting F4:0F:1B was manufactured by or for Cisco Systems, Inc.