IPv6 is the most recent version of the Internet Protocol (IP). IP is an addressing scheme used to identify computers on the Internet. The most common version in use currently is IPv4, however, there are not enough IPv4 addresses to satisfy current and future demand. On the 14th September 2012 RIPE began to allocate addresses from its last remaining IPv4 block , this situation means devices can not easily have their own IPv4 addresses.
In order to provide more addresses for devices IPv6 was created. Instead of using 32 bit addresses it provides 128 bit addresses. This means instead of having ~4.2 x109 there are ~3.4×1038 addresses available. Whilst IPv6 provides enough addresses for current and all predicted demand it is not compatible with the old IPv4 system. It is possible to run both IPv4 and IPv6 simultaneously, which is what most computers do without anyone noticing.
As well as providing more address space IPv6 also has mechanisms for extending the functionality provided. One of these extensions is 6LoWPAN which is designed to reduce the overhead of encapsulating data into an IPv6 packet. While being able to give global IPv6 addresses to nodes is useful for experiments it is not essential – as a local network could work just as well – but we wanted to test all the possibilities!
So essentially this lets us have a powerful modern Internet connection to/from the systems.