In the early 1990s, the Internet Engineering Task Force (IETF) grew concerned about the issues with IPv4 and began to look for a replacement. This activity led to the development of IP version 6 (IPv6). IPv6 overcomes the limitations of IPv4 and is a powerful enhancement with features that better suit current and foreseeable network demands.

Improvements that IPv6 provides include:

The 32-bit IPv4 address space provides approximately 4,294,967,296 unique addresses. Of these, only 3.7 billion addresses are assignable, because the IPv4 addressing system separates the addresses into classes, and reserves addresses for multicasting, testing, and other specific uses.

As shown in the figure, IP version 6 address space provides 340,282,366,920,938,463,463,374,607,431,768,211,456, or 340 undecillion addresses, which is roughly equivalent to every grain of sand on Earth.