EUI-64

A way to build a 64-bit IPv6 interface ID from a MAC address: split the MAC, put ff:fe in the middle, and flip the 2 bit of the first byte. With the prefix 2001:db8:10::/64, the laptop's MAC 02:00:00:00:10:20 gives the address 2001:db8:10::ff:fe00:1020.