How many IPv4 addresses are there?

An acquaintant posted the following question on an IRC channel earlier today:

How many IPv4 addresses are there?

The quick and simple answer is 232 = 4,294,967,296 addresses.

Is this an accurate answer? Yes, in a strict interpretation of the original question.

A far more interesting puzzle is if you want to account for all the IPv4 addresses usable on the public internet. Continue reading How many IPv4 addresses are there?