What is wrong with IP version 4 Address?
The IP version 4 Address has the crisis, because it is only has the 2^32 addresses in total – around 4.29 billion. They have been all assigned to various institutes (university, internet service provider, etc.)
IP version 4 have not been running out, because many IP version 4 address are not used, and in the hands of the institutes like Massachusetts Institute of Technology, and the company like International Business Machines.
More IP version 4 address are available to be assigned and more will be traded or sold, but they will be not enough to be assigned in the next two years.
The solution is IP version 6 addresses, which will replace the IP version 4 addresses. They will have 2^128 addresses in total – around 340,282,366,920,938,000,000,000,000,000,000,000,000, because they will have the hexadecimal.