IPv6 was developed to improve on its predecessor protocol, addressing many of the limitations that became apparent as the Internet grew. However, to generate improvements, a completely new protocol that was not backwards-compatible with the existing IPv4 specification was required.
This created a technological hurdle that few have been willing to clear. Rather, the industry has found ways around the deficiencies of IPv4. Of all of the benefits that IPv6 brings to protocol technology, the increase in IP addresses is the most notable.
If the internet is to continue to grow and support new applications, the world will need more IP addresses.Technologies such as Network Address Translation (NAT) are stop-gap measures to buy time. The precise point in time when we will run out of IPv4 addresses is unknown, though speculation indicates that it will occur before 2020, perhaps as soon as 2008. Indeed, that alone may be enough to drive the adoption of IPv6.