"The drop-dead deadline for external Web sites to support IPv6 is January 1, 2012," warns John Curran, President and CEO of the , which distributes blocks of IP addresses to North American ISPs and other network operators. "When we get to the end of 2011, we're going to have a lot of people connecting over IPv6 and that doesn't bode well for the content providers who don't support IPv6."
IPv6 is the long-anticipated upgrade to the Internet's main communications protocol, which is called IPv4.
IPv4 uses 32-bit addresses and can support around 4 billion IP addresses. The Regional Internet Registries including ARIN Tuesday that more than 90% of IPv4 addresses have been allocated.
IPv6 is designed to solve the problem of IPv4 address depletion. It uses a 128-bit addressing scheme and can support so many billions of IP addresses that the number is too big for most non-techies to understand. (IPv6 supports 2 to the 128th power of IP addresses.)