[Thiez]

> IPv6 has several advantages, including a much larger address space. IPv4 had only 2^32 addresses, less than one per person on earth. IPv6 has 2^128 addresses, an immensely larger number which is not expected ever to be exhausted. Estimates are that this is enough to assign 100 IPv6 addresses to every atom on earth.

Yeah, so that's overestimating the number of IPv6 addresses by quite a couple of orders of magnitude. This website estimates the number of atoms at 10^49 to 10^50, whereas 2^128 is in the order of 3 * 10^38. https://www.fnal.gov/pub/science/inquiring/questions/atoms.h... Perhaps the writer was thinking of grains of sand instead of atoms? I'm not sure how many sand we have, but it's probably more in the 2^128 ballpark.

[throw0101a]

Another way of thinking about it:

* Stars in the Milky Way: 400 Billion

* Galaxes in the universe: 2 Trillion

So (4x10^11)x(2x10^12)=8x10^23 stars in the universe.

* Size of IPv6 address space: 3.4x10^38

Find the ratio between addresses and stars:

* 3.4x10^38 / 8x10^23

IPv6 offers about 430 trillion times more addresses than estimated stars in the universe.

From Tom Coffee's presentation "An Enterprise IPv6 Address Planning Case-Study"

* https://www.youtube.com/watch?v=7Tnh4upTOC4

[JuettnerDistrib]

Perhaps in more human terms:

On the surface of the Earth, there are 8.4 IPv4 addresses per km^2. Not counting the oceans, that would be 28 IPv4 addresses per km^2 land.

IPv6 gives 10^17 addresses per mm^2 (yes, square millimeter).

In terms of volume, 10^8 IPv6 addresses per mm^3 throughout the Earth.

[throw0101a]

> IPv6 gives 10^17 addresses per mm^2 (yes, square millimeter).

Not that it practically matters, but: is that the 'full surface' or not counting the oceans (land-only)?

[JuettnerDistrib]

Full surface including oceans. I actually got something like 6.6 * 10^17 per mm^2, but who's counting?