Why is IPv4 so bad?

It’s unanimous: The current Internet Protocol, IPv4, is inadequate for the surging demand for Internet connectivity across every aspect of the global economy. Primarily, it’s because the structure of IPv4 addresses limits how many can be created, but there are security, workload, architecture, and mobile-device-compatibility issues as well.

Today’s IP addresses consist of four numeric sequences separated by periods, like this: 201.65.2.57. That is a 32-bit IP address (four sequences contains 8 bits). Because of the proliferation of IP addresses through the bi-level architecture that assigns IP numbers (to a network and the hosts on that network), the 32-bit addressing schema of Internet Protocol version 4 holds the distinct possibility that those four billion addresses will soon be exhausted.