Here’s something you may or may not have realized about IPv4 and IPv6.
An IPv4 IP address is comprised of four octets (8 bits), with each of those four octets capable of going from 0 to 255. And, by the way, it’s sheer coincidence that IPv4 has 4 octets; the two 4s are completely unrelated.
Now, multiply 255 four times and you get a massive number – 4,228,250,625.
This, dear reader, is the total number of available IPv4 addresses. Yet, we’ve already completely exhausted all 4.3 billion addresses.
Enter IPv6 which effectively takes us from the four octets of IPv4 to a staggeringly vast pool of 128 bits.
If you want to know how many addresses that is, I caution you – don’t try using your calculator; it might, well, go up in smoke! Why, you ask? Well, that number is 2 to the power of 128 OR 3.4 x 10 to the power of 38 OR, get this, 340 undecillions (or sextillions). To understand its magnitude, let’s just say there aren’t even enough stars in the universe to total that number!