What this means
The IEEE assigned the MA-L block 18EF63 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 18:EF:63, it is Cisco Systems, Inc hardware.
Frequently Asked Questions
Who owns MAC prefix 18EF63?
18EF63 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 18EF63?
Any network device with a MAC address starting 18:EF:63 was manufactured by or for Cisco Systems, Inc.