As of February 3, 2011, the Internet Assigned Numbers Authority (IANA) allocated the remaining of the last five /8 of the IPv4 address space to the Regional Internet Registries. With that – the free pool of IPv4 addresses that are available is now fully depleted.
The IPv4 addresses look like:
where as the new IPv6 addresses look like:
ARIN still has a pool of IPv4 address space and they will continue to do so in accordance to the policy in the Number Resource Policy Manual. The depletion of the IANA IPv4 pool will have a direct impact on a number of policies. For information see: https://www.arin.net/resources/request/ipv4_depletion.html