When you set up IPv6, you may need to set up your own local, non-routable IP addresses on your network - similar to the older RFC1918 blocks. RFC-4193 addresses (no pun intended) this issue. Your IP address block assigned should be generated randomly from the fc00::/7 block. As IETF hasn't formalized fc00::/8, addresses should be assigned out of fd00::/8. This means that your resulting IPv6 networ