ReadWriteEnterprise

It's an IPv4 world today, but the days of IPv4 are numbered.

As of February 2011, the Internet Assigned Numbers Authority (IANA) had allocated all remaining public IP address ranges to the five global regional Internet registries. A quick look at this IPv4 Exhaustion Counter below shows a total of 13.24 /8 (8-bit) IPv4 address ranges remaining, for a total of less than 3,400 remaining unallocated IPv4 addresses. Essentially, this means
IPv4 is played out.

Earlier this spring, as anticipated, the last of the IPv4 address blocks was given to the regional Internet registries that dole them out to ISPs and other corporations. Unlike many predictions that go back dozens of years, we have run out of room. Yes, it will take several months before the world is completely run out of address space, and you might be able to find an unused Class C range here or there. But for the most part, you need to get cracking on a transition plan for your company to migrate towards IPv6 now.