When the Internet began, IPv4’s possible 32-bit 4.3 billion addresses looked like more than enough. Things have changed.
We’re running out of IPv4 addresses, the 32-bit numeric addresses that network devices need to connect to the Internet. All those mobile devices that we love so much like iPhones, tablets, and iPods are gobbling down IPv4 addresses like an elephant does peanuts. For the longest time, we managed to avoid running out of IPv4 addresses with the use of technologies like Network Address Translation (NAT) and Classless Inter-Domain Routing (CIDR), but those haven’t been enough.
According to the Number Resource Organization (NRO), the group that oversees the allocation of all Internet number resources, announced in January 2010 that less than 10% of available IPv4 addresses remain unallocated. As Axel Pawlik, chairman of the NRO, said in a statement, “It is vital that the Internet community take considered and determined action to ensure the global adoption of IPv6. The limited IPv4 addresses will not allow us enough resources to achieve the ambitions we all hold for global Internet access.”