IPv4 and IPv6


As you may have heard there is no more space on the Internet. The addresses available to websites and other internet locations under IPv4 will run out very soon, which potentially means no more new websites. Yippee! But, is IPv4 the IPocalypse or the Y2K of 2011?

The Internet operates by transferring data in small packets that are independently routed across networks as specified by an international communications protocol known as the Internet Protocol. Each data packet contains two numeric addresses that are the packet’s origin and destination devices. Since 1981, IPv4 has been the publicly used Internet Protocol, and it is currently the foundation for most Internet communications.

Internet Protocol version 6 (IPv6) is a version of the Internet Protocol (IP) that is designed to succeed Internet Protocol version 4 (IPv4). The Internet’s growth has created a need for more addresses than IPv4 has. IPv6 allows for vastly more numerical addresses, but switching from IPv4 to IPv6 may be a difficult process.

IPv4 allows approximately four billion addresses (it’s a 32-bit system so actually there are 4,294,967,296 many of which are private and reserved, like the type addresses used locally by network equipment and computers). IPv6 is 128-bit and so allows 2 to the power of 128, that’s 340 undecillion, which is plenty go round if we can make the leap.

There are lots of organisations “squatting” on unused blocks of IP addresses, and Stanford actually released some of its IPs to free up addresses. So, if more of those could be released it would stave off the IPocalypse for a few more months.

The problem is that IPv6 does not play nicely with IPv4, it effectively is a parallel, independent network and exchanging traffic between the two requires special gateways. In December 2010, despite marking its 12th anniversary as a Standards Track protocol, IPv6 was only in its infancy in terms of general worldwide deployment; Google reported that penetration was less than one percent of Internet-enabled hosts in any country in 2008. Thankfully, IPv6 has now been implemented on all major operating systems in use in commercial, business, and home consumer environments and firmware for domestic routers should be available with relative ease.

So, what’s the problem? Why don’t we simply make the leap from IPv4 to IPv6?

Bottom line is money.

On 8 June, 2011, Google, Facebook, Yahoo!, Akamai and Limelight Networks will be first to carry out an IPv6 24-hour “test flight“, which is meant to motivate organizations across the industry – Internet service providers, hardware makers, operating system vendors and web companies – to prepare their services for IPv6 to ensure a successful transition as IPv4 addresses run out. Whether this persuades anyone to do the necessary will depend on budgets, profit margins and whoever wants to untie the purse strings first.