IPv6 addresses are longer than IPv4 addresses, and are so capable of greater expression. Given an IPv6 address, conventions and standards allow us to draw conclusions about how IPv6 is being used on the node with that address. We show a technique for analysing IPv6 addresses and apply it to a number of datasets. The datasets include addresses seen at a busy mirror server, at an IPv6-enabled TLD DNS server and when running traceroute across the production IPv6 network. The technique quantifies differences in these datasets that we intuitively expect, and shows that IPv6 is being used in different ways by different groups. Â© 2008 Springer-Verlag Berlin Heidelberg.