The IPv4-addresses-running-out-stories are getting old and so are the if-only-they-made-it compatible-with-IPv4-comments.
IPv4 uses 32-bit addresses. You can't stuff more addresses in 32 bits. So you need to make the addresses bigger. If you do that it is not IPv4 anymore. If you would even change one bit in IPv4 and make IPv4.1, still all devices using IPv4.0 need to be updated. So we need a *new* protocol with bigger addresses, 128 bits, which is IPv6. And while they were at it, they improved some other things that we didn't like about IPv4.
IPv6 was designed to run alongside IPv4 from the beginning. They work independently and you device might have IPv4, IPv6 or both and you would not notice the difference.
The reason we're dragging this so long:
- it's different, scary!
- we might need to buy new/updated device/software and it costs money!