The end of IPv4 is nigh - well nearly. We are approaching the depletion of the current unallocated IPv4 address space with only seven /8 IP blocks remaining in the IANA (Internet Assigned Numbers Authority) pool. IP addresses are a limited resource with only around 4 billion available to be used. A new protocol, IPv6, has been developed which operators are slowly starting to support which will eventually replace IPv4, but it is likely IPv4 will still be used for many years to come.
IANA control the allocation of these IP address blocks to the regional IP address registries and once there are only five remaining blocks, they will be handed out, one each, to each of the Regional Internet Registries (RIR's) who handle allocations in their local area, (such as ARIN in North America and RIPE NCC in Europe). The current predicted date for IP's running out is March 5th 2011, but some suspect this could be sooner. When this date comes, the RIR's are expected to last for around 8 months before depletion of their available address space occurs, with the Asia/Pacific region (managed by APNIC) expected to run out first.
When this happens, we may start to see a shift change on the Internet with IPv6 starting to become more widely used and available as IPv4 becomes a scarce resource. There is the possibility of a two-tiered Internet where some who are stuck in an IPv4 world are not able to access sites which are hosted only on IPv6. Currently few broadband providers in the UK offer IPv6 connectivity, even though AAISP has offered it since 2002. Broadband router manufacturers are also lagging behind in support for IPv6 although this is improving slowly.
Here at thinkbroadband, we have supported IPv6 for over two years. To see if you are connecting to us via IPv6 or to find out more information, see our IPv6 guide. Our advanced ISP search also lets you find broadband providers who offer IPv6, although we only have three listed at the moment: AAISP, Exa Networks and IDNet - others are known to be in trials at the moment. If you are a UK broadband provider and currently support native IPv6, we'd love to hear from you.