Web addresses could run out as soon as November and to raise public awareness Google and Facebook will switch their websites to a new system for one day in June.
 On June 8, Google, Facebook, Yahoo and a host of other leading web companies    will turn on a new way of running web addresses. The system, called IPv6, is    designed to stop the world running out of the web addresses that underlie    the locating of websites and devices. Currently, just 0.2 per cent of web    users have access to the new protocol, however. 'World IPv6' Day is designed    to encourage its adoption.  
  Vint Cerf, one of the web’s founding fathers, is leading a global campaign to    encourage web service providers and IT managers to switch from the current    system, IPv4, to IPv6. The new standard offers many trillions of new web    addresses, but cannot be accessed from modems and routers that only use    IPv4. It is likely, however, that most of the changes needed will take place    without consumers losing access to any part of the web because they will be    part of the standard software and hardware upgrade cycle.  
  The availability of new web addresses will, it is hoped, allow more connected    devices, such as tablet computers, as well as permitting more mundane    devices to gain web addresses. Mr Cerf gave the example of a cork in a wine    bottle using a web address to tell its owner when the optimal time to drink    it is and its location.  
  Writing on the Google Blog, Network Engineer Lorenzo Colitti said that “Google    has been supporting IPv6 since early 2008, when we first began offering    search over IPv6. Since then we’ve brought IPv6 support to YouTube and have    been helping ISPs enable Google over IPv6 by default for their users. On    World IPv6 Day, we’ll be taking the next big step. Together with major web    companies such as Facebook and Yahoo!, we will enable IPv6 on our main    websites for 24 hours.” 
He added, however, that “Our current measurements suggest that the vast    majority (99.95%) of users will be unaffected. However, in rare cases, users    may experience connectivity problems, often due to misconfigured or    misbehaving home network devices.
          