When you get an IPv4 address from your ISP, that’s all you get – an address. Maybe if you run a business, you get 3 or 4. With IPv6, your ISP gives you at least 264 addresses; that is 18,446,744,073,709,551,616 for those counting. IPv6 simplifies routing by making all sites /48, and all subnets /64. With 128 bit addressing, this means you will practically never run out of addresses in your allocated subnet. Want to give your coffee maker its own global address? Do it man, live the dream Both of the above IPv6 ISPs will give you multiple /64 or /48 subnets for free. It feels almost wasteful, particularly after you take a look around.