Hi Towdie,
In reality the router does one more thing when creating the IPv6 address using EUI-64. The MAC address is chopped in two pieces but it will also “flip” the 7th bit. When it’s a 0 it will make it a 1 and the other way around. Here’s an example for the MAC address I used in this tutorial:
CC0A.180E.0000
Each hexadecimal character represents 4 binary bits:
C = 1100
C = 1100
0 = 0000
A = 1010
Let’s put “CC” in binary behind each other:
11001100
EUI-64 will flip the 7th bit of this address so it will become:
11001110
Let’s calculate that back to hexadecimal:
1100 = C
1110 = E
So the first part becomes CE0A. I’ll create a tutorial for this process and the reason behind it later on, but hopefully this explains the outcome of the address.