What is reason for the failure of IPv4?
I wouldn’t exactly call IPv4 a failure. Its what runs on most of the computers in the world today. There was a thought that IPv4 would be doomed by now, but NAT has rescued it for the time being. That said, there is a move to migrate the internet to IPv6 will provide many orders of magnitude more network addresses. It’s anticipated that IP communications will proliferate to all kinds of devices, requiring many more addresses. IPv6 has a few difficulties itself. The address is longer, reducing the payload in packets. Higher speed networks shoulc make this a non-issue. And god knows what router tables are going to look like.
