Earlier this week I wrote how European IPv4 addresses have now all been allocated. The IPv6 address space is extremely bigger than IPv4 is. IPv4 has 2^32 possible addresses, as they have a length of 32 bits. IPv6 is 128 bits long, allowing 2^128 addresses.

We have an IPv6 address with our fiber to the home connection (currently 500Mbit symmetrical, which is actually a step down from the 1Gbit symmetrical we had before). I asked our provider what type of address allocation they use for IPv6. They allocate a (currently recommended) /48 block to us. A /48 IPv6 block contains 2^(128−48) = 2^80 addresses. The total IPv4 address space is 2^32 addresses. So we actually have an available address space at home that is 2^16 (65.536) times larger than the square of the total number of IPv4 addresses (2^16*2^32*2^32=2^80). These are mind bogglingly large numbers.