For larger enterprise, this may mean building their own private internet. How does IPv6 change this? Either way, you have to use IP addresses assigned to you (

For larger enterprise, this may mean building their own private internet. How does IPv6 change this? Either way, you have to use IP addresses assigned to you (public IPv6 addresses, or private IPv4 addresses) if you want to interface it to the public internet. Your physical firewall and router setup isn't going to change much, if at all. If your private network will never be connected to the internet, you can use any old addressees and routing schemes you want. Nobody will care what you do because there is no risk of collision with anyone else.