Introduction to IPv6

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:


Each hexadecimal character represents 4 binary bits:

C = 1100
C = 1100
0 = 0000
A = 1010

Let’s put “CC” in binary behind each other:


EUI-64 will flip the 7th bit of this address so it will become:


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.