As you all are already aware that IPv4 is draining out and companies are looking forward to switch to IPv6, but something is going fishy here. Microsoft invested a huge amount of 7.5million USD in purchasing the IPv4 addresses from Nortel, which is a dying company and has been declared bankrupt in January 2009.
IPv4 is a 32bit Internet Protocol system which can hold only up to 4 billion addresses. The Internet agencies knew that 4billion addresses will short fall very soon, because of the massive avalanche of people getting online. Every mobile phone and some gadgets are getting online too in comparison of the computer systems around the world. So the IT industry started working on the newer version called IPv6 (IP version 6) since last 10 years.