What is this nonsense about 2^128 being a "number is too big for anyone but a mathematician to understand"? Most computing professionals should understand powers of 2... it's what we do! It's so incredibly simple I will explain it here. 2^20 = 1MB, 2^30 = 1GB, 2^40 = 1TB. Notice a pattern? How about this: 2^1 = 2, 2^2 = 4, 2^3 = 8, 2^4 = 16, 2^5 = 32. As you go up one power of 2, the result doubles. So what's it like going from 2^32 (IPv4) to 2^128 (IPv6)? Take the number of IP addresses in IPv4 (2^32, aka about 4.3 billion) and double it... 96 times! (128-32=96) You don't have to be a mathematician to understand this.